344 
A CXIXOPTERYGII. 
Caturus (Conodus) chirotes (Agassiz). 
[Plate VII. figs. 2, 3.] 
1839. Eugnathus cheirotes , L. Agassiz, Neues Jahrb. p. 118. 
1842-44. Euqnathus chirotes, L. Agassiz, Poiss. Foss. vol. ii. pt. ii. 
p. 102, pi. lvii. b. 
1844. Conodus ferox, L. Agassiz, ibid. p. 105 (name only)* [Portion 
of jaws ; British Museum.] 
1890. Eugnathus (?) chirotes , Woodward & Sherborn, Catal. Brit. Foss. 
Vertebrata, p. 77. 
Type. Imperfect fish ; British Museum. 
The type species of the undefined genus Conoclus , attaining a 
length of about 0*75. Length of head with opercular apparatus 
apparently exceeding the maximum depth of the trank and con¬ 
tained about four times in the total length of the fish. External 
bones ornamented in part with sparse tuberculations; maxilla 
thick but not much deepened, the hinder two-thirds of its dentigerous 
margin concavely arched, and the height of the middle teeth not 
equalling the depth of the bone at their point of insertion ; supra- 
maxilla sparsely tuberculated, half as long as the maxilla ; pre¬ 
maxillary teeth very large, apparently equalling in size those of 
the middle of the dentary, which are somewhat tumid at the base ; 
splenial teeth relatively very small and numerous, stout and not 
much curved; enamel restricted to the apex in all the teeth. 
Scales for the most part smooth, but some of those of the flank 
exhibiting longitudinal crenulations. 
Form. Sf Loc. Lower Lias : Dorsetshire. 
P. 3643. The type specimen described and figured by Agassiz, loc. 
cit .; Lyme Begis. The head seems to have been somewhat 
deepened in the fossil by the upturning and fracture of 
the cranium, while the jaws are displaced downwards. 
The otic elements are well-ossified and the thin dermal 
cheek-plates are conspicuous. The maxilla is much 
fractured and imperfect, but some of the slender teeth in 
its hindermost portion are well shown ; one very large 
tooth on the premaxilla is also preserved. The mandible 
is obscured, and only one of its moderately large anterior 
teeth can be seen. The middle portion of the preoper- 
eulum is coarsely rugose, and the same ornament appears 
slightly on other fragments of the external plates. The 
ossifications in the sheath of the notochord are much 
crushed, but evidently consist of separate pleurocentra 
