346 
CROSSO PTERY GII. 
regarded as the type of a distinct species, Rhizodus aneeps , J. S. 
Newberry, Trans. New York Acad. Sci. vol. vii. (1888), p. 165, 
and Pakeoz. Pishes N. America (Mon. XT. S. Geol. Surv. no. xvi. 
1889), p. 191, pi. xliii. fig. 1. 
An imperfect Bhizodont laniary tooth, perhaps of the same 
species, from the same formation and locality, is theoretically 
associated by Newberry with a fossil which appears to the present 
writer to be the superficially calcified meckelian cartilage of an 
Elasmobranch. These two specimens (in the Museum of Columbia 
College) form the basis of a supposed genus Coelosteus, J. S. New¬ 
berry (Trans. New York Acad. Sci. vol. vi. 1887, p. 137), with the 
single species, C.ferooc ( ibid ., and Paleeoz. Pishes N. America, 1889, 
p. 190, pi. xxxv. figs. 1-4). 
Rhizodias ornatus* Traquair. 
[Plate XII. figs. 5-9.] 
1836. MegalichtJiys hibberti , Agassiz & Hibbert (errore), Trans. Boy. 
Soc. Edinb. vol. xiii. pi. viii. fig. 2 (scale). 
1866. Rhizodus, J. Young, Quart. Journ. Geol. Soc. vol. xxii. p. 599 
(scales only). 
1875. Rhizodus hibberti, B. H. Traquair (non Ag. & Hibb.), Ann. Mag. 
Nat. Hist. [4] vol. xv. p. 266. 
1875. Rhizodus, L. C.Miall, Quart. Journ. Geol. Soc. vol. xxxi. p. 624, 
woodc. (inferior aspect of head, showing jugular plates). 
1877. Rhizodus ornatus, B. H. Traquair, Proc, Boy. Soc. Edinb. vol. ix 
p. 659. 
Type. Anterior portion of fish ; Edinburgh Museum. 
A species much smaller than R. hibberti. Head, opercular 
and clavicular bones, and also scales, externally ornamented with 
very coarse tuberculations, usually confluent into nodose, often 
reticulating ridges. Clavicle and infraclavicle relatively narrower 
antero-posteriorly than in R. hibberti, and the scales thicker. 
Form, § Log. Calciferous Sandstones and Lower Carboniferous 
Limestone Series : South Scotland. 
1 nless otherwise stated, the following specimens were obtained 
from the Blackband Ironstone (Lower Carboniferous Limestone) of 
Gilmerton, near Edinburgh :— 
P. 3345. Head and anterior portion of trunk, viewed from the ventral 
aspect. The mandible and portions of the jugular plates 
and operculum exhibit the superficial ornamentation of 
blunt tubercles and large, nodose, reticulating ridges; while 
