1895. ] NEW YORK ACADEMY OF SCIENCES. 117 
The proportions of newberryi, when reduced, may then be 
expressed in the terms of the former species, thus : 
Sylert. newberryi. 
Distance from centre of orbit to origin of pec- 
toral (unit of comparison),....... Seo dacs 2 1 
Length of pectoral, measured axially. See pal 2 
e ‘*s _proximo- —istad, <i.» ae 1 3 
Distance from hinder margin of pectoral to 
Orion) Of vembraly. wr). on a : NESE Seabee 1 2 
Greatest apparent breadth of trunk, skeet a see 1 1 
It will accordingly be seen that Cladoselache newberryi was 
proportioned not unlike the recent eel-like frilled shark, Chlamy- 
doselache. It differed from other known Cladodonts in the 
smaller size of the pectoral fins and the greater interval between 
the paired fins (ef. Fig. III.). The snout, only in part pre- 
served in the fossil, seems to have been longer than that of 
Fyleri. The head at eye region appears notably broad. 
In addition to these differences in proportions, newberryt is 
readily distinguished by the structure of its pectoral fin (see 
Fig. IV.). Although the fin rays agree substantially in number 
and relative sizes, their mode of arrangement is clearly different 
from that of fyleri; the rays are notably compacted antero-pos- 
teriorly, and have lost to some degree the graceful curve in their 
placement. They have thus become set rigidly almost at right 
angles to the fish’s axis, and in their straightness and compact- 
ness, their row of graded sizes appears clearly suggestive of the 
fin spine of Acanthodian. The entire fin is narrower and more 
acutely pointed than that of fyler. 
Cireum orbital plates, although not perfectly preserved in the 
fossil, are relatively larger than those of JSylert, and appear less 
numerous, doubtful in this character perhaps on account of im- 
perfect preservation (Fig. VIII.). 
The basalia of the left ventral fin are imperfectly preserved 
(Fig. V.). Their number and position, however, vary but little 
from the conditions of fyleri. Six basalia are to be determined. 
Near by, anteriorly, is the impression of what must be re- 
garded as a coprolite, while still further forward (Fig. III., A) 
is an entire coprolite well preserved. The latter (Fig. Vil. ) 
is especially interesting since it furnishes a cast of the intestinal 
wall and gives definite evidence as to the presence of a spiral 
valve. This structure, accordingly, maintained in the general- 
ized Cladodont; and that the intestinal septa were here low and 
numerous is most significant phylogenetically. Its condition in 
this form, as the nearest known ancestor of Selachians, would, 
