270 CATALOGUE OE THE BLASTOIDEA. 



Remarks. We quite agree with Prof. F. Roemer and with Messrs. Dnjardin and 

 Hupe that McCoy's Codaster acutus is nothing more than a variety of his other 

 species. In fact we go further, and believe it to be only the young condition 

 of C. trilobatus. According to usual custom this, being the first form described 

 by McCoy, ought to be considered as the type of the genus Cadaster. But to accept a 

 young and immature stage of any species as a generic type when we are in possession 

 of the perfect and mature form would be highly unphilosophical, and lead to endless 

 confusion. 



The specimens we desire to retain under the varietal name acutus differ from 

 C. trilobatus in possessing a smaller calyx, a more acute and less trilobed base, with 

 a smaller number of side plates and hydrospires. The latter vary according to the 

 age of the individual from two to five in number, and in exceptional cases there are 

 six (PL XIII. figs. 4, 9-12). We have seen examples with both the intermediate 

 numbers, three and four. In the very young state (PL XVI. fig. 2) the ambulacra 

 occupy a relatively much larger portion of the summit than they do in the more 

 advanced condition. With growth the ambulacra become narrower and longer, and 

 the interradial spaces wider, the hydrospires increasing in number accordingly. The 

 sharper and longer proportions of the calyx in this variety, or young condition, which- 

 ever it may be called, is quite in accordance with the observations of Mr. Wachsmuth 

 on calycular growth amongst the Blastoidea : , as we have undoubted evidence in the 

 series of specimens before us of the rapid lateral expansion or widening out of 

 the calyx as compared with its longitudinal growth. 



We believe, guided by some old labels attached to specimens, that it was to this 

 form of Codaster that Messrs. Austin contemplated applying their name Pentrc mites ? 

 astraformis. There is also little doubt that Prof. Roemer was correct in referring the 

 figure of Pentrcmitcs pentagonalis, Forbes, to this variety. On the other hand, we 

 believe that our eminent friend was misled in giving on de Verneuil's authority 

 Astrocrinites, Cumberland, as another synonym of Codaster acutas, for we have no 

 evidence that Cumberland even proposed this name for any genus of Pelmatozoa. 



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

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



Genus PH^XOSCHISMA, E. & G, 1882. 

 Pentremitidea, Carpenter (pars), Report Brit. Assoc, for 1881 [1882], pt. 2, p. G3L 

 Phanoschisma, E. & C, Ann. & Mag. Nat. Hist. 1882, vol. ix. p. 226. 



Gen. Char. Calyx elongately clavate, or obpyramidal, with deeply excavated 

 summit. Basal plates forming an elongated cup. Radial plates each bear three 

 more or less distinct folds diverging from the lip ; the two contiguous limbs forming 



1 Report Geol. Survey Illinois, ltb3, vol. vii. pp. 34'J, 350. 



