DESCEIPTI0N8 OF THE SPECIES. 269 



in any way refer to a form resembling Codaster, unless it be the "new genus" from 

 Bolland, referred to under the Echinoidea '. We are inclined to this view, from the 

 context of certain labels accompanying the specimens. It is not impossible that the 

 figure given by the late Mr. Billings 2 as that of Codaster aoutus, McCoy, is in reality 

 a representation of the present species, judging from the number of hydrospire-slits 

 in each interradius. 



The hydrospire-slits, as a rule, arc eight in number (PI. XIII. fig. 10), and some 

 large specimens possess ten (PI. XIII. fig. 8), but we have not seen examples with 

 more. On the other hand, we have some specimens possessing all the characters of 

 C. trilobatus, in which there are only six hydrospire-slits in each interradius. 



The flattened summit of C. trilobatus (PI. XIII. figs. 1, 3, 4, 9-12) at once distin- 

 guishes it from all the American species of the genus, in each of which there is a 

 distinct radial sinus so that the dorsal surface of the radials is divisible into body and 

 limbs (PI. XII. figs. 2, 3, 5, 6), whereas in C. trilobatus there arc really no true limbs 

 at all (PI. XIII. figs. 3, 8-12, 15). This is especially the case in the only species 

 from the American Carboniferous, C. Whitei, Hall. 



The ornamentation of the calyx was not described by McCoy, and from the peculiar 

 state of preservation of the large number of specimens is seldom visible. The radial 

 plates are concentrically imbricate-striate, but on the basal plates the stria) following 

 the margins of the plates become festoon-shaped (PL XIII. figs. 2, 3, 13). 



Localities and Horizon. Bolland, Lancashire; Settle, Yorkshire: Carboniferous 

 Limestone. (Presented by the late J. Rofe, Esq., F.G.S.) 



Codaster trilobatus, var. acutus, McCoy, var. 



(PL XIII. tigs. 9-12, 15; PL XVI. fig. 2.) 



Pentremites ? astraformis, T. & T. Austin (MS.) , Ann. & Mag. Nat. Hist. 1842, vol. x. p. 1 1 1 . 

 Pentremites pentagonalis, Forbes, Mem. Geol. Survey Gt. Brit. 1818, vol. ii. pt. 2, 



p. 529, f. a. 

 Codaster acutus, McCoy, Ann. & Mag. Nat. Hist. 1849, vol. iii. p. 251. 

 Codaster acutus, McCoy, Brit. Pal. Foss. 1851, fasc. 1, p. 123, t. 3d. f. 7 (Codonaster in 



expl. of plate). 

 Codonaster acutus, Roemer, Archiv f. Naturgesch. 1851, Jahrg. xvii. Bd. i. p. 385, t. 8. 



f. 2,a-d (excl. syn. Astrocrinites) . 

 Codonaster acutus, Roemer, Bronn's Lethrea Geogn., Dritte Aufl. 1852, Theil 2, p. 285, 



t. 4'. f. ll,a-c. 

 Codonaster acutus, Bronn, Klassen unci Ordn. Thier-Reichs, I860, Bd. ii. t. 23. f. 6, a-c. 

 Codonaster acutus, Dujardin & Hupe", Hist. Nat. Zooph. Echinod. 18G2, p. 102, t. 2. f. 17. 

 Codaster acutus, E. & C, Ann. & Mag. Nat. Hist. 1882, vol. ix. p. 235. 



1 Op. cit. p. 208. 



2 American Journ. Sci. 1809, vol. xlviii. p. 79, f. 8; Canadian Nat. A- Geol. 1SG9, vol. iv. p. 288, f. 8; 

 Ann. & Mag. Nat. Hist. 1870, vol. v. p. 261, f. 8. We suspect that this figure was copied from Itoemer. 



