7 I 8 E. C. CASE 



Phil. Soc, Aug. 1884, and Proc. Am. Assoc, and Sc, 1884, Vol. XXXIII), 

 and Case (Trans. Am. Phil. Soc, 1899, Vol. XX.) One specimen shows the 

 proximal end with articular cavity for the humerus formed by the scapula 

 and coracoid. The scapula is perforated by a foramen just above the artic- 

 ular face. Plate III, Fig. 3. [No. 6540.] 



Himieri. — There are four types of humerus. One, the largest, is relatively 

 much shorter and stouter than the others, and is remarkable for the strong 

 articular faces and the generally robust character. The proximal end is 

 marked by prominent rugosities and the deltoid crest is laterally expanded, 

 much more so than in the other forms, and very rough. Length .14™; width 

 of the head at the deltoid ridge .057"". Plate III, Fig. 4, a, b. [No. 6541. 



The second form has a much longer shaft than the first, and at all points 

 shows a greater elegance of form at the expense of strength, but the extrem- 

 ities are as well formed and the articulate surfaces as distinct. This probably 

 belongs to one of the described forms of Clepsydrops from Illinois, probably 

 the largest, C. pedunculatus. A smaller form of the same type is represented 

 by the distal end of another humerus, which is perfectly preserved. The 

 entepicondylar foramen is large and elongate, the ectepicondylar foramen is 

 represented by a notch, as in all the Pelycosanria ; the head for the proximal 

 end of the radius is prominent, almost hemispherical and well formed, it is 

 continuous with the articular surface for the ulna. Height of fragment .o66 m , 

 width at deltoid ridge .030'". Plate III, Fig. 5, a, b, c, and Fig. 6. [Nos. 

 6542, 6543. and 6575.] 



The third type is represented by the distal end of a very small form sim- 

 ilar in many respects to the foregoing, but with the internal process rounded 

 and truncated and the entepicondylar foramen missing. The form is very 

 small and the shaft of the bone was slender, but the distal extremity shows a 

 strong development. The process forming the ectepicondylar notch is promi- 

 nent, and the portion of the distal extremity on either side of the articular 

 surface extended below the surface instead of lying in a line with it or not 

 reaching so far. This form may be the same as the "No. 6" mentioned by 

 Cope in his first contribution to the fauna of the Texas Permian, but as it was 

 not described nor figured, it is impossible to say definitely. The humerus 

 "No. 6" is regared by Cope as belonging to a possibly fossorial animal, this 

 may be true of the present form, but there is no vertabrae in the collection 

 which could go with such a type. Plate III, Fig. 7. [No. 6544.] 



The fourth and last type differs very considerably from the others. The 

 ends are concave, as if they had been cartilaginous in life, and there are no 

 articular surfaces distinguished. The extremities are at right angles to each 

 other, and there is a small deltoid process, continuous with the proximal 

 end. The entepicondylar foramen is present, but there is no trace of an 



