354 
CEOSSOPTERYGII. 
Form, Log. Lower Carboniferous : Horton Bluff, Nova Scotia. 
Hot represented in tbe Collection. 
An undetermined small species, with teeth resembling those of 
S. sciuroides (Traquair, Trans. Boy. Soc. Edinb. vol. xxx. p. 18) is 
indicated by the following specimens :— 
P.4054. Two teeth, 0-01 in length, incurved at the apex; Calci- 
ferous Sandstones (Cement-stone Group), Eskdale, "Dum¬ 
friesshire. Purchased , 1883. 
P. 4054 a. Oval scale, 0’038 in long diameter; Eskdale. 
Purchased , 1883. 
Scales, with associated teeth, from the Calciferous Sandstones of 
Pitcorthy, Eife, are also named Strep sodas minor , B. H. Traquair, 
Proc. Boy. Soc. Edinb. vol. xvii. (1890), p. 393. [Edinburgh 
Museum.] 
Other scales much resembling those of Strepsodus have been 
described from the Upper Devonian of Mimers Dal, Spitzbergen, by 
E. B. Lankester, Handl. k. Svenska Yetensk. Akad. vol. xx. no. 9 
(1884), p. 5, figs. 7-12. [State Museum, Stockholm.] Compare also 
Sauripterus (p. 364). 
A fragmentary scale from the Chatham Series of North Carolina, 
figured under the name of Pabdiolepis speciosus by E. Emmons 
(Manual Geol. ed. 2, i860, p. 183, fig. 161), also exhibits some 
resemblance to Strepsodus. 
IP** 
^10°f>d6% ■ 
Genus RHIZODOPSIS, Young. 
[Quart. Journ. Geol. Soc. vol. xxii. 1866, p. 596 L] 
A 
Syn. Dittodus , B. Owen, Trans. Odontol. Soc. vol. v. 1867, p. 325 (in 
part). 
Ganolodus, B. Owen, ibid. p. 354 (in part). 
Characodus , B. Owen, ibid. p. 366. 
Gastrodus , B. Owen, ibid. p. 370. 
Orthognathus, T. P. Barkas, Coal-Meas. Palaeont. 1873, p. 38. 
Body much depressed anteriorly, with narrow ovoid scales, of 
which the exposed portion is covered with a thin film of ganoine, 
while the inner face is marked by a median boss and punctations 
posteriorly. Teeth round in section, smooth. Yertebrse ring-shaped. 
Eirst dorsal fin opposed to the pelvic pair, and the second dorsal to 
the anal; tail heterocercal, the caudal fin rhomboidal in form. 
1 This definition is said to be based upon the unpublished observations of 
Huxley. The generic name is incidentally mentioned by Huxley, Mem. Geol. 
Surv. dec. xii. (1866), p. 31, footnote. 
