CHIROCESTRIDiE. 
101 
P. 6328. Imperfect jaws with remains of the anterior part of the 
cranium, displaying the palatine and prefrontal bones 
and the ossified sclerotic. The articular end of each 
mandibular ramus is also well shown. Purchased, 1891. 
Ichthyodectes arcuatus, Cope. 
1875. Portheus arcuatus, E. D. Cope, Vert. Cret. Form. West (Rep. 
U.S. Geol. Surv. Territ. vol. ii.), p. 204 ( non pi. xlvii. figs. 7-9). 
1878. Ichthyodectes arcuatus, E. I). Cope, Proc. Amer. Pliil. Soc, 
vol. xvii. p. 177. 
1892. Ichthyodectes polymicrodus, A. R. Crook, Pakeontogr. vol. xxxix. 
p. 112, pi. xvi. [Imperfect skull with jaws; PaUeontological 
Museum, Munich.] 
1892. Ichthyodectes polymicrodus = 1. arcuatus, E. D. Cope, Amer. Nat. 
vol. xxvi. p. 942. 
1 898. Oil/icus arcuatus, O. P. Hav, Amer. Journ. Sci. [4] vol. vi. p, 230. 
1898. GilUctis polymicrodus, 0. P. Hay, ibid. p. 230. 
1900. Ichthyodectes occidcntalis, F. B. Loomis, Paleeontogr. vol. xlvi. 
p. 242, pi. xxiii. figs. 1-6 1 . 
Type. Maxilla ; Cope Collection. 
The type species of tho so-called Gillicus, with maxilla attaining 
a length of about O'l. All bones comparatively delicate. Oral 
border of maxilla strongly sinuous, sharply concave just below and 
behind the palatine articulation ; dentary comparatively deep, and 
its oral border slightly concave ; teeth very small, about 100 in the 
maxillary series. 
Form. § Loc. Upper Cretaceous (Niobrara Group) : Kansas. 
P. 9201. Vertically crushed cranium and imperfect jaws, associated 
with vertebral centra ; Elkader, Logan Co., Kansas. 
Purchased, 1900. 
P. 8902. Fragments of cranium associated with vertebrae ; Elkader. 
By exchange, 1898. 
Ichthyodectes serridens, sp. nov. 
[Plato VIII.] 
Type. Head, &c. ; British Museum. 
Head and jaws closely resembling those of I. arcuatus, but 
anterior mandibular teeth relatively larger, and maxilla apparently 
more slender. 
Form. Sf Loc. Albian : Kent. 
' The extended median dorsal fin in t he restoration of this species published 
by Loomis is entirely hypothetical and seems to be based on the erroneous 
assumption that such a fin occurs in Spathodactylus. 
