98 KANSAS UNIVERSITY SCIENCE BULLETIN. 



has not been observed in any of the specimens. The epihyal 

 is represented in several of the other specimens: plate XIII, 

 figure 1, eh; also figure 3, eh; and in the American Museum 

 specimen, No. 1837. In Doctor Hay's description of this speci- 

 men he speaks of this element as an opercular (Hay, 1903). 

 There were then no specimens of this species, with the oper- 

 cular present, in the American Museum. The ceratohyal (pi. 

 XI, fig. 2, ch) is lying in position relative to the epihyal. With 

 the exception of the hyomandibular (fig. 1, Iim) , the remain- 

 ing elements of the hyoid series have not been observed in 

 any of the specimens. The left post-temporal is lying just 

 caudad to the skull, not quite in position. A portion of the 

 supraclavicle is attached to the caudal end of this bone. The 

 other post-temporal, shown in figure 3, is attached to the dorsai 

 end of the supraclavicle (scl) . In figure 1 the left post-tem- 

 poral seems to have been moved from its natural position to- 

 ward the median line of the skull. In all probability the nar- 

 row cephalic end should lie directly over the left epiotic, and 

 the slender process (fig. 1, p) should attach to the mesial sur- 

 face of the left pterotic. Since no supratemporal has been ob- 

 served in so complete a specimen it would seem that this ele- 

 ment may not occur in Enchodus doUchus. The supraclavicle 

 is not quite complete in this specimen. (A complete one is 

 shown in plate XIII, figure 1, scl). This bone attaches to the 

 dorsal process of the clavicle (fig. 3, cl). It probably over- 

 lapped with the clavicle about one-half its length. The length 

 of these suspensory bones indicates that the pectoral fins were 

 very close to the head, and that Enchodus dolichus was not so 

 deep in the region of the pectoral fins as Enchodxs petrosus. 

 (Compare the supraclavicles of this species with those of the 

 specimen shown in plate V, scls.) Plate II, figure 3, shows the 

 supraclavicle of an undetermined species. This is much longer 

 relatively than the supraclavicles of Enchodus dolichus. The 

 pectoral girdle and fins are very complete. Plate XI, figure 3, 

 shows the dorsal aspect with all parts below the supraclavicles 

 in position. The shape of the clavicle is best seen in another 

 specimen (pi. XIII, fig. 3, cl). The hypercoracoids (he) are 

 complete. They are semilunar in outline, the straight edges 

 having been directed caudo-dorsally in life. The ventral ed^e 

 joins the hypocoracoid and the dorsal wing is free. Near their 

 ventral border is a large oval foramen. Caudo-dorsally from 



