December .8, 1891.] 



SCIENCE. 



34S 



pbint may have been the obstruction. At that time the water, 

 filled with floating ice, may have made the strias as it flowed over 

 the top of this dam ; until tinally it cut a chasm through the ob- 

 struction 



Another fact suggesting the same probability is that from this 

 anticline for many miles up the river there are considerable Loess 

 deposits. These may have been made before the obstruction was 

 was cut through. 



But while the strise at this place might be thus accounted for, 

 this would give no sufficient explanation of the presence of the 

 bowlders, etc., scattered over these hills many miles from the 

 river and several hundred feet above its bed. In fact there are 

 now three or four feet of clay or soil overlaying the very rocks 

 which htve the supposed glacial scratches on them, and this clay, 

 etc , has in it pebbles and small bowldere of the same kind as 

 those scattered over the ."surface of thi.^s section. 



So, upon the whole, I think bowlders, striae, and all are of true 

 glacial origin. J. W. Kirkpatrick. 



Fayette, Mo.. Dec. 9. 



Mexican Featherwork. 



'•The most famous surviving specimen is the standard, described 

 by Hochstetter, which is now in the Vienna Ethnographical Mu- 

 seum " (Science. Dec. 4, p. 311, 3d col., top). This splendid piece 

 of old Mexican fealherwork is the subject of special publications 

 by Mrs. Julia Nuttall, entitled "Das Praohtstiick altmexicanischer 

 Federarbeit aus der Zeit Montezuma's iin Wiener Museum '" (Re- 

 ports of the Dresden Museum, 1887), and "Standard or Head- 

 dress" (Archaeol. and Ethnol. Papers, Peabody Mus., Harvard, 

 1888, Vol. I., No. 1). Both these papers are elaborately illus- 

 trated and bring forward overwhelming evidence to show that 

 what has hitherto been considered an Aztec standard is really a 

 head decoration. X. 



Kansas Mosasaurs. 



Hitherto, no adequate description or figure has ever been pub- 

 lished of the complete anatomy, or even of the skull, of any mem- 

 ber of the extinct group of reptiles known as the Mosasaurs or 

 Pythonomorpha. Fortunately, however, my able friend Dr. Baur 

 has recently had the opportunity to thoroughly study an excellent 

 spt'cimen of one of the Kansas forms, and his figures and descrip- 

 tions, when published, will doubtless be of great interest. The 

 University of Kansas has, within recent years, obtained one of the 

 most valuable collections of these animals now extant. Among 

 this material, there is one specimen of especial interest, by reason 

 of its remarkable completeness, consisting, as it does, of skull and 

 connected vertebrae to the tip of the tail, with ribs, extremities, 

 and cartilages in position. 



Before briefly describing this specimen, which belongs to a 

 difl'erent genus from that studied by Dr. Baur, I m-^y be permitted 

 to offer the following remarks upon the nomenclature of the 

 Kansas forms, based upon larger opportunities than have been 

 enjoyed, I believe, by any other investigator. 



The following generic names have been proposed or adopted by 

 various writers for the diiferent forms of these reptiles froju the Kan- 

 sas Cretaceous: Liodon O.ven, Plafecarpus Cope, CUdastes Cope, 

 Sironectes (,'ope, Lestosaurus Marsh, Tylosaurus Blarsh, Edesto- 

 sawrMS Marsh, and i?o?osfmrMS Marsh. Three genera, only, can be 

 readily and positively distinguished among the material. The names 

 now recognized for these, and with justice, are: Liodon. Platecar- 

 2ms. and CUdastes. Two others, Sironectes and Holosaums, have, 

 possibly some claims for recognition, but the evidence in favor of 

 either is, so far, very weak. Holosaurus is not synonymous with 

 Sironectes, as afBrmed by Cope and followed by Dollo. Holosaurus 

 rests almost solely upon a single character, the non-eniarginate 

 coraooid ; in other respects nothing is known to separate it from 

 Platecarpiis. In fact, Platecarpus itself may possess this very 

 character. That the character was not considered by the author 

 of Holosaurus as important is evidenced by the following. In 

 the American Journal of i^cience (Vol. iii., June, 1872, p. 5 of 

 separate) he says: 'There is certainly noemargination in the cora- 

 ooid of CUdastes, Kdestosaurus, and Baptosaurus, as specimens 



in the Yale Museum conclusively prove." A Kgure of the coracoid 

 of CUdastes (Edestosaurus) dispar, given in the same paper, shows 

 the bone entire. In the same paper in which Holosaurus is figured 

 and described (Amer. Jour. Sci., vol. xix., pp. 83-87) a restora- 

 tion is given of the shoulder girdle of ^^Edestosaurus dispar 

 Marsh," in which the coracoid is very conspicuously seen to be 

 emarginate. That this was not an error on the part of the artist, 

 1 can vouch, for the specimen from which the figure was made 

 was collected and restored by myself. There is a lack of consis- 

 tency here somewhere. 



A fuller discussion of the genera and generic characters of the 

 Kansas material, I leave to a future occasion. As there have been 

 more rhan twice too many generic names given; so. too, it is pretty 

 evident that there is even a greater proportion ot synonyms amo- g 

 the specific names. The specific nomenclature is, at present, 

 however, a subject of great intricacy, of which no one is ma.ster. 

 Mr. E. C. Case of the State University will shortly publish a jjaper 

 on this subject. 



With these general observations, I will now give a brief de- 

 scription of the specimen above mentioned; a fuller des'i'iption, 

 with illustrations, will appear later. The specimen is a CUdastes 

 (Edestosaurus) and, from Mr. Case's studies, probably C velox 

 Marsh, which is apparently the same as the earlier described C. 

 cineriarum Cope. The specimen measures, from the tip of the tail 

 to the tip of the rostrum, one hundred and thirty-nine aTid one- 

 half inches, inclu ling altogether one hundred and seventi-en ver- 

 tebrae, the whole regionally divided as follows : skull, seventeen 

 and one-half inches; cervical region, seven vertebrae eight and 

 one-half inches; costifarous, post-cervical region, thirty-four ver- 

 tebrae, fifty- four and one- half inches; non-rib or chevron-bearing 

 region, seven vertebree, eight and one half inches; chevron be.ir- 

 ing region, sixty-eight vertebras, fifty-one and one half inches. 

 All of the cervical vertebrw, save the atlas, have ribs, those of the 

 axis, though, are very small, increasing in the last cervical to 

 about three inches in length. The first to the ninth dorsal, or 

 true thoracic, ribs, those articulating with the cartilaginous sternum 

 through the intenention of cartilasiinous ribs, are of nearly equal 

 length, about eight and one- half inches, and are moderately curved. 

 The eleventh dorsal rib is but four inches long, and thence to the 

 thirty-fifth or last, they decrease gradually to about two inches. 

 The rib-bearing processes, as well as the vertebrse themselves, do 

 not differ much throughout the series. The longest costal cartUage 

 preserved does not measure over four inches; this will give, with 

 the sternum and vertebrae, a total circumference of the thorax not 

 exceeding thirty inches. 



Immediately following the last costiferous vertebra, are seven 

 vertebrae n ith elongate transverse processes, and without chevrons. 

 From the position of the pelvis, it was evidently attached to the 

 first of these vertebrae, none of which can be properly called 

 lumbar. With the first chevron-bearing vertebra, the transverse 

 processes begin to decrease in length, and finally disappear in the 

 twenty-fifth or twenty-sixth. 



The tail is elongate, slender, and compressed, the spines and 

 chevrons having their greatest length only about one foot from 

 the exli-emity, where the tail measures nearly six inches in height. 



Of the paddles little need be said. The hind pair was decidedly 

 smaller and less strong I ban the fore pair, the latter having an 

 outstretched expanse of about thirty inches. 



As a whole, this, one of the most specialized species of the most 

 specialized genus of known extinct or recent lizards, was most 

 marvellously serpentine and slender in its build, with an elongate, 

 flattened, pointed head, short neck, very slender body, long, lithe, 

 and vertically flattened tail, small but broad and strong paddle- 

 like limbs It is doubtful whether there was ever another verte- 

 brated animal so admhably adapted for rapid and varied move- 

 ments through the water. Though the smallest of the Mosasaurs, 

 it was by far tlie most graceful in its proportions, the most delicate 

 and exquisitely conslructeil in its details. 



It is certain that none of the Kansas forms of this order were 

 covei-ed with bony scutes, as described by Marsh, the bones so 

 described being, undoubtedly, sclerotic plates. 



S. W. AVILLISTON. 



Uulverdlty of Kacsas, Dee. I. 



