Hoplophoneus primaevus Leidy and Owen.

The original type of this species is figured in the The Ancient Fauna of Nebraska (1853). Later Leidy figured two skulls in the Extinct Fauna of Dakota and Nebraska, remarking that the larger one might be the skull of an old male, and that the original type was somewhat intermediate in size. The determination of the variation due to sexual characters seems impossible in the case of the extinct cats. However, the material which is available, shows that there are two types represented by these two skulls, the skeletons referable to the types differing more markedly than the skulls. Inasmuch as Leidy's original type agrees more closely with the smaller one, the difference being about such as is presented in any of the species of Machairodonts, it is taken as representative of H. primaevus. In the Princeton collection there is a fairly complete skull (number 11,013) and two nearly complete skeletons (numbers 10,741 and 10,934), with the latter skeleton there is also most of the skull. This makes it possible to correlate the skull with the skeletons and give the measurements of the species. The skull is short and high in the frontal region, the orbit horizontally oval, the posttympanic process short, the glenoid drooping considerably below it.

The skeleton is not rugose and the limb bones have slender shafts as in Dinictis felina. The dental formula is I, C, Pm, M; the second superior premolar probably being constantly present.

Length of skull, condyles to premaxillaries, Leidy's type

This species is proposed as representative of Leidy's second type or H. primaevus. It has its most perfect type in the skeleton and skull (No. 650) determined as H. primaevus by Osborn and Wortman, the measurements of which were published in the American Museum Bulletin, Vol. VI, 1894, p. 228, along with those of H. insolens (H. occidentalis) and which I give here, adding the measurement of the skull. The species is represented in the Princeton collection by specimen

number 10,647, consisting of a fairly well preserved skull and mandible together with a humerus and portions of other limb bones. The skull is relatively large compared with the skeleton. The limb bones are rugose and have stout shafts, being very similar to those of Dinictis fortis, and are thus very different from those of H. primaevus. Dentitition: I, C, Pm 23, M }.

Length of skull, condyles to premaxillary border

180 mm.

Hoplophoneus oreodontis Cope.

This species is Cope's type of the genus. I introduce it here for the purpose of mentioning a complete skull in the Princeton Museum (number 10,515) which supplements the original type and is, therefore, used here for comparison. The approximate lengths of the femur and tibia are based upon the lengths of these bones associated with the type skull, the epiphyses being lost. Dentition: I, C Pm 23, M †. †

This species from the John Day is the smallest of the genus and at the sametime the most peculiar. Cope has pointed out its specific characters as follows: Space for the temporal muscle relatively short; brain capacity large; profile of the face very convex; sagittal crest horizontal; occiput vertical; no paroccipital processes; orbit vertically

In my description of D. fortis, American Naturalist, June, 1895, I compared the skeleton with that of H. occidentalis, following the description of that species as given by Wortman and Osborn, which the foregoing determination of its skeletal characters shows to be incorrect. D. bombifrons which I described at that time I now find to be a synonym of D. fortis; the skull described being correlated with the skeleton and portion of a skull of D. fortis by means of specimen number 1400 of the American Museum.

oval.

Dentition: I, C, Pm 2, M /, the third premolar being much reduced.

Length of skull, condyles to premaxillary border (ap

There are thus six species of Hoplophoneus, disregarding H. strigidens Cope, which being based upon a fragment of a canine exhibiting a peculiar form, is not characterized by any features which refer it to Hoplophoneus rather than any other genus. With the exception of H cerebralis they are all from the White River. They present an interesting series both in the size of the skulls and skeletons. The accompanying series of femora give an idea of the relative characters of the skeletons of the larger members of the genus as regards size and strength. Unfortunately nothing is known of the skeleton of H. cerebralis, but judging from the size of the skull it would be the smallest of the series, although probably not much smaller than that of H. oreodontis. In restoring the femur of H. occidentalis I am indebted to Dr. Williston for information as to its length.

The series of skulls figured in outline when taken in connection with the series of femora give an idea of the relative size of the species. The gradation in size is for the most part comparable with the gradation in size of the skeletons. Each species has shown, from careful comparisons and measurements of all the available material, a limited amount of variation, but in no case losing its identity when both the skull and skeleton are taken into consideration.-GEO. I. ADAMS, Fellow of Princeton College.

EXPLANATION OF PLATES.

Plate I.

Fig. 1.-Hoplophoneus cerebralis (after Cope).

Fig. 2.-Hoplophoneus oreodontis (number 10,515 Princeton Museum).

Fig. 3.-Hoplophoneus primaevus (after Leidy).

Fig. 4. Hoplophoneus robustus (number 650 American Museum). Fig. 5.-Hoplophoneus insolens (number 11,022 Princeton Museum). Fig. 6.-Hoplophoneus occidentalis (after Williston).

All X

Plate II.

Fig. 1.-Hoplophoneus occidentalis (Leidy's type).

Fig. 2.-Hoplophoneus occidentalis (number 1,047 American Museum). Fig. 3.-Eusmilus dakotensis (after Hatcher).

Fig. 4.-Hoplophoneus primaevus.

Fig. 5.-Hoplophoneus robustus.

Fig. 6.-Hoplophoneus insolens.

Fig. 7.-Hoplophoneus occidentalis.

All XI

The Goldbearing Quartz of California.-The salient characteristics of the gold quartz veins of California are briefly given by Mr. Waldemar Lindgren in a paper recently published, and the results of his observations are thus summarized:

"The auriferous deposits extend through the state of California from north to south, in an irregular and unbroken line.

"The gold quartz veins occur predominantly in the metamorphic series, while the large granitic areas are nearly barren. The contact of the two formations is not distinguished by rich or frequent deposits." "The gold quartz veins are fissure veins, largely filled by silica along open spaces, and may dip or strike in any direction.

"The gangue is quartz, with a smaller amount of calcite; the ores are native gold and small amounts of metallic sulphides. Adjoining the veins, the wallrock is usually altered to carbonates and potassium micas by metasomatic processes.

"The veins are independent of the character of the country rock, and have been filled by ascending thermal waters charged with silica, carbonates and carbon dioxide.

"Most of the veins have been formed subsequent to the granitic intrusions which closed the Mesozoic igneous activity in the Sierra Nevada."

Regarding the origin of the gold, the author speaks with reserve. He points out the possibility of its derivation from the surrounding rocks, which theory, however, is not altogether satisfactory. He then states the following facts and the conclusion based upon them:

First, the gold quartz veins throughout the state of California are closely connected in extent with the above described metamorphic series and that the large granite areas are almost wholly void of veins, though fissures and fractures are not absent from them.

"Second, that in the metamorphic series the gold quartz veins occur in almost any kind of rock, and that if the country rock exerts an influence on the contents of the veins, it is, at best, very slight.

"Third, that the principal contact of the metamorphic series and the granitic rocks is in no particular way distinguished by rich or frequent deposits.

"It is further apparent that gold deposits have been formed at different periods, though, by far, most abundantly in later Mesozoic times. Some of these later veins may have been locally enriched by passing through earlier impregnations in schist or old concentrations in the sandstones and conglomerates of the metamorphic series, the gold contents of which have, however, only been proved in isolated cases.

"These considerations strengthen the belief that the origin of the gold must be sought below the rocks which now make up the surface of the Sierra Nevada, possibly in granitic masses underlying the metamorphic series." (Bull. Geol. Soc. Am., Vol. 6, 1895.)

Precambrian Sponges.-M. L. Cayeux has published a preliminary note on the spicules of sponges found in the Precambrian beds of Bretagne. The author describes the different forms of the spicules, gives their dimensions, the mode of fossilization, and the probable causes for their fragmentary condition. The principal conclusions derived by M. Cayeux from his researches are (1) numerous spicules of sponges of various species are found in the Precambrian phtanite formations of Bretagne, and (2) that all the orders of sponges with silicious skeletons are represented in these formations.

A resume of the facts ascertained concerning this interesting fauna is given by the author as follows:

"It is impossible not to be struck by the ensemble of the sponges of the phtanites of Lamballe. Even excluding all the spicules which, although they certainly are sponges, yet are too fragmentary for exact identification, there remains an assemblage of forms which points to a very complex fauna.

"In the light of our present knowledge this fauna appears to be composed of Monactinellidæ, probably abundant, Tetractinellidæ, relatively rare, numerous Lithistidæ, and a few Hexactinellidæ. All the orders of Silicea are represented. The branching off of the sponges is then plainly as early as the base of the Precambrian of Bretagne.

"The oldest beds in which any remains have been found belongs to the Archean of Canada. M. G. F. Matthew has described Cyathospongia? eozoica from the Lower Laurentian of St. John (New Brunswick) and Halichondrites graphitiferus from the Upper Laurentian of the same region.

"Cyathospongia? eozoica may be a species of Hexactinellidæ, and Halichondrites graphitiferus must be referred either to Monactinellida or to Hexactinellida. The authenticity of these fossil sponges has been put beyond a doubt by M. Hermann Rauff.