thorax; and twelve, the abdomen. At some time during the development of the insect, appendages are present upon all except the first, third and twenty-first segments. The frons, clypeus, labrum and compound eyes are parts of the first segment. The second segment bears the antennæ, the fourth the mandibles, and the fifth and sixth the two pairs of maxillae. The hypopharynx does not belong in the series of appendages but is formed by a folding of the ventral portions of the fourth, fifth and sixth segments. The cerci, contrary to the views of some authors, are the true appendages of the twentieth (eleventh abdominal) segment. Considerable emphasis is laid upon the similarity between the first and twenty-first segments, in their relations to the openings of the alimentary canal, in being free from appendages, in the lateral position of their ganglia and in the relative changes of the appendages of the adjoining segment. Concerning the position of the genital openings, Heymons reiterates his former opinion that they may belong primitively to the tenth segment, their position in the ninth being a secondary development.-G. M. WINSLOW. The Coxal Glands of Thelyphonus caudatus.-In a brief note in the Zoologischer Anzeiger, Dr. Theo. Adensamer adds a few facts to complete Sturany's work on the Arachnoidea. The two glands occur between the gastric coca and the muscles, and extend as unbranched and unlobed sacs to the abdomen. From the anterior end of each extends a simple duct to the coxæ of the first pair of legs through which they open. A thin chitinous intima was distinguished in the ducts. An histologically differentiated portion of the gland corresponding to Lankester's medullary substance and Sturany's Marksub sanz was not found. The following table shows the location of the openings of the glands in the several groups: Limulus, openings in the 5th appendages. Scorpio, openings in the 3d pair of legs 6th appendages. = 3d appendages. a. Tetrapneumous, openings in the 3d pair of legs = = 5th append 5th appendages. b. Dipneumous, openings in the 1st pair of legs 3d appendages. Phalangida, openings in the 3d pair of legs Acarina, openings in the ? pair of legs = ? 2 XVIII, p. 424. -F. C. K. Cross Fertilization and Sexual Rights and Lefts Among Vertebrates.-The November number of this journal, page 1012, under the title "Sexual Rights and Lefts," called attention to sexual peculiarities I had recently discovered in certain Cyprinodonts. At that time no satisfactory explanation of the purpose or origin of the strange conditions offered itself. At present I would like to note in these pages what upon further consideration appears to me the best solution of the problem. Additional study has satisfied me that the sexual conditions in the genus Anableps prevent close "inbreeding," or, in other words, they secure cross fertilization. What in certain plants is attained by means of short stamens with the long ones is in these fishes realized by sinistral and dextral males and females. This is a view in the case of Anableps that brings us in face of probable benefit from the novel features, and of the possible causes of their evolution. As bearing on the inception of the dextral and the sinistral peculiarities we must consider the habit possessed by so many of these fishes of swimming in pairs, side by side, a habit that induced Professor Agassiz to name one of the genera Zygonectes, that is yoke swimmers. The acquisition of more or less of a dextral or of a sinistral tendency would not be at all unnatural in each of a pair habitually swimming side by side in the same relative positions to one another. It may be that cross fertilization will afford an explanation of conditions somewhat similar among molluscs. While writing of matters concerning the publication "The Cyprinodonts," it should be mentioned, as kindly pointed out to me by Dr. A. Smith Woodward of the British Museum, that the name of one of the new genera, Glaridodon, was recently preoccupied among fossils, and it may be well here to discard that name (p. 40) for the term Glaridichthys.-S. GARMAN, Cambridge, Mass. Abnormal Sacrum in an Alligator.-Among a lot of young alligators procured from New Orleans for the University of Chicago one in which the skeleton was prepared, showed a very peculiar variation in the pelvic region there being three instead of two sacral vertebræ. There are as usual 24 presacral vertebræ. The 25th has the sacral ribs inclined backwards and becoming slender. The 26th has strong thick ribs, and the 27th, the first caudal in normal specimens, has also well developed ribs articulating strongly with the ilium. The 27th is seemingly biconvex. The first chevron is attached between the 28th and 29th and is, therefore, in the normal position as regards the serial number of the vertebræ, but is attached to the first vertebræ the last sacral instead of the second. The whole pelvis has migrated backwards one vertebræ, the first true sacral tending to become a lumbar and the first caudal has become a sacral. The two side are strikingly symmetrical. The figures giving views from above and below are natural size and include the 24th-28th vertebræ. H. The other known cases of variation in the sacrum of Crocodilia are, as far as I am aware, as follows: Rheinhardt1 examined 11 specimens and found 3 abnormal. 1. Alligator sclerops Schn.: Last lumbar become a sacral; 23 presacrals. 2. Crocodilus acutus: 3 sacrals, 3 plane-convex, 1st caudal concaveconvex and bearing a chevron, thus the first caudal has become a sacral, 23 presacrals. 3. Crocodilus acutus: First caudal has become a sacral, 24 presacral. Baur' reported two cases. 1. Gavialis gangeticus: 25 presacrals. One intercalated between the 9th and 10th. 2. Alligator mississippiensis: Last lumbar become a sacral, showing on one side a small sacral rib and which does not reach ilium, 23 presacrals. Baurs reported three cases. 1. Crocodilus acutus: A specimen in the museum at Cambridge, Eng. shows on the right side of the 25th vertebra a strong and separate rib, on the left side the rib is smaller and coössified with the centrum. The 26 shows typical sacral ribs. The 27th shows on the left side a 1(Anomalier i Krydsvirvlerne hos Krokodelerne, Copenhagen, 1873, and Sur les anomalies des vertèbres sacrées chez les crocodilieus. Jul. de Zoologie T. III, No. 4. Paris, 1874.) Zoologischer Anzeiger, IX Jahrg., No. 238, 1886. Osteolog. Not. über Reptilen. Revision meiner Mittheilungen (Zoolog. Anz. XII, Jahrg., No. 306, 1889. in Zoologisher Anzeiger, mit Nachträgen.) strong free rib and on the right side a weaker rib but free. The 28th biconvex. 2. Crocodilus acutus: Two specimens in the Royal museum at Leiden have only 23 presacrals.-E. C. CASE. The Polar Hares of Eastern North America, with Descriptions of New Forms.-In 1819 Captain John Ross, in the fourth Appendix of the second (octavo) edition of his "Voyage of Discovery" in Baffin's Bay, described a hare which he procured in Baffin Land, in latitude 73° 37'. To this animal he gave the name "Lepus arcticus Leach," stating at the end of his description that "Dr. Leach thinks it to be very distinct from the common White Hare of Scotland (Lepus albus Brisson) and equally so from the Lepus variabilis, Pallas." Ross then makes a reference to "Appendix No. V," of the same volume, which he evidently supposed would contain Leach's description of the same animal. Leach's chapter on the " New Species of Animals" obtained by Ross, however, does not come in appendix number five but is part of the same appendix in which Ross' description appears. It is on page 170, while Ross' description is on page 151. Leach evidently described the same specimen which Ross had in hand, but gave it the name Lepus glacialis. Owing to its precedence in paging, Dr. J. A. Allen' rightly adopts the name arcticus for the American Polar Hare, glacialis of Leach becoming a synonym. The question has been raised by my friend, Mr. Outram Bangs, whether Ross, and not Leach, should have credit for the name arcticus. We may justly infer from Ross' description that he intended that Leach should have this credit and that he published it with such intention. He must have consulted with Leach about its relations to the European and Scottish Hares and quotes Leach in his diagnosis, using, without doubt, the specific name then suggested by Leach. The fact that Leach gave it another name does not affect the status of the one given by Ross, nor weaken Leach's claim to it. From the present custom, not definitely formulated in our American Ornithologist's Union's canons of nomenclature, I see, however, no alternative but to call the Baffin Land Hare, Lepus arcticus Ross." Mon. N. Amer. Rod., 1877, p. 288. 2 Some authorities prefer that sole credit for the name of a species be given to the person to whom the original publisher of that name ascribes the origin of the name, writing it in this case Lepus arcticus Leach. The A. O. U., with one (or two ?) ex. ceptions, adopts the reverse rule in their check list of birds, and would make it read Lepus arcticus Ross. Neither method does justice either to the public or to Dr. J. A. Allen (1. c.) concludes that the American Polar Hare is not specifically separable from the European L. timidus (=variabilis Auct.), and the deficient material which he had for examination at that time probably justified such a verdict as the safest one, especially when we consider the standard of species and varieties adopted at that date by American mammalogists. Through the kind liberality of Messrs. G. Brown Goode and F. W. True of the Smithsonian Institution, and of Mr. Outram Bangs of Boston, I have been favored to examine, in connection with the specimens in the Academy of Natural Sciences of Philadelphia, an unusually large series of skins and skulls of the Polar Hares of America and north western Europe. The results of this study, so far as they relate to the Polar Hares of eastern North America, and Scandinavia may be summed thus briefly. 1. LEPUS TIMIDUS L. Scandinavian Polar Hare. Type locality (hypothetically restricted), Southern Sweden. Nasals nearly or quite reaching to anterior vertical plane of premaxillaries. Posterior frontal swelling on a plane with the postorbital processes. Upper incisor with transverse sectional diameter greater than the longitudinal diameter; the chord of the arc of its exposed surface (with skull, minus mandibles, resting on a plane horizontal surface) is vertical; the radius of the arc described by the incisors is one-eighth (%) of the basilar length of skull; their inner faces indented by a deep broad sulcus and they are rooted on the premaxillaries at or slightly anterior to the inferior maxillo-premaxillary sutures. Roots of lower incisors extending to base of pm, 1. Summer pelage; above blackish brown, sprinkled with gray; ears darker, but not black, tail white, dark above. 2. LEPUS ARCTICUS "Leach," Ross. Baffin Land Polar Hare. Type locality, lat. 73° 37', northern Baffin Land, southeast of Cape Bowen. Size larger (?) than timidus, with relatively smaller and wider skull and shorter ears. Skull of the same type as timidus, with the following differences: Nasals, rostrum and incisive foramina relatively those personally interested. I suggested (Proc. Acad. Nat. Sci., Phila, 1895, p. 395), that both the publishing and the manuscript or verbal authority for such names should be indicated. My friend, Witmer Stone, has suggested an improvement on my formula which I heartily endorse, viz.. that instead of “ Rana clamitans Bosc., Mss., Sonn., Latr." (1. c.), it should read Rana clamitans " Bosc.," Sonn. & Latr., and the Baffin Land Hare would read Lepus arcticus "Leach," Ross. This comports far better with our motto that, "Zoological nomenclature is a means, not an end, in zoological science." |