340 {Jan. 5, 
Cope.] 
The spines already noticed are quite flat, without serrate edge, but with 
some rugosities near the edge on one side only. There are no grooves on 
the upper side, but the dense bone is delicately striate ; distally grooved. 
Measurements. 
M. 
Leneth premaxillary. each caries Shoe tiecs STOR OME RIE fa be bee 0.033 
Depth ME Sn Carpe Fa AN Rabe Ret fe apihs re eters 0.045 
Depth maxillary at condyle............se eee seen eee 037 
Thickness ‘ just behind condyle...... esd sabes a eOLe 
Length mandibular ramus.......-++.+.+- pean ee 
ee angular process..... Wasi vie JReredcn give doe dati pn 
Depth at coronoid process...... ae? aeapeee ie Saeed hee 058 
fry o SYMIPD YSIS. s fice ese os Diced eel ae Wan eitenets 3 O41 
Length of eight vertebra..........2. cece ee ees <atha 212 
Width of articular face.... .030 
ee MOT a sears s cet 004. 
“flat spine at middle Na ade AD 
Length “¢  @ragment). . DD 
“ condyle inferior quadrate....... PR Oe be ver OR 
The scales associated with this species were thin and cycloid, and dif- 
ficult to preserve. 
From near the 
moky Hill River, Kansas. 
IcHTHYODECTES CTENODON. Cope. 
(Proc. Amer. Philos. Soc., 1870, Nov. Hayden’s Geol. Surv., Wyoming, 
etc., 1871, p. 421 part.) 
Found by Professor Mudge on the North Fork of the Smoky Hill River ; 
common in many other localities. 
ICHTHYODECTES HAMATUS. Cope. sp. nov. 
Represented by a considerable number of remains of an individual 
from the blue cretaceous shale near Russell Spring, on the Smoky Hill 
River. 
The characters which distinguish this species from J. anaides, are 
numerous, but they are less marked when compared with those of J. cten- 
odon, partly because the premaxillary bones of the latter have not been 
preserved. In the first place, the dentary bones of the two are of equal 
length and support the same number of teeth; it is concave at the prox- 
imal part of the tooth line, but is straight in the corresponding part of 
I. ctenodon. The end of the dentary is furnished with a strong obtuse 
process or hook, directed upwards and forwards, not seen in I. ctenodon. 
The maxillary behind the premaxillary is, in this species, thickened, and 
with two articular surfaces, the proximal looking outwards, the distal 
inwards and separated by an oblique ridge from the condyle. In J. etenodon 
