16 DK. P. H. CAEPENTEE ON CEETAIN POINTS 



that Beyrich's genus is figured iu the atlas to Queustedt's Eucri- 

 niden, though the type is described in the text as a Cystid*. 

 S. A. Miller t has proposed to replace Lecythiocrinus, White, by 

 Menocrinus, on the ground that the former name is pre-occupied 

 by Lecythocrinus of Mliller and Zittel. But tlie two names are 

 not identical ; and even if they were, there is some doubt as to 

 the validity of Miiller's genus, so that there is no need for the 

 introduction of Menocrinus. Miller % notices the difference be- 

 tween the two American species in the number of infrabasals, 

 though he persists in calling them basals, and he regards it, if 

 really existing, as of generic value ; but he appears never to 

 have heard of Codiacrinus and Hyj^ocrinus. The similarity of the 

 plates in the dorsal cup in the latter type to those of Codiacrinus 

 and Lecythiocrinus seems to me to indicate clearly that it is a 

 Crinoid and not a Cystid. The same view has been taken by 

 Bather §. 



Cryptocrinus is also a very puzzling form (PI. I. fig. 9). I 

 have endeavoured to reconstruct the calyx of G. cerasus from 

 Yon Buch's projection ||, which does not seem to be altogether in 

 accordance with his description or other figures. He supposed 

 that one of the five plates (^Seitenasseln) which rest upon the 

 three infrabasals was divided horizontally into two parts, which 

 I have marked respectively 7 and 13. The five plates above these 

 {Scheitelasseln, Von Buch) would then come to be radials. His 

 projection shows an additional plate between 9 and 10, which is 

 not at all clear in his two views of the cup from above and the 

 side. I have indicated it in fig. 9 by a dotted line, and have 

 marked it .r. It would seem to belong to the peristomial series 

 rather than to that of the dorsal cap, and may be left out of con- 

 sideration for the present. I am inclined to think, however, that 

 plate 13 is not the upper half of a divided basal, as supposed by 

 Yon Buch, but that it should rather be regarded as radial D, 

 which has been displaced downwards and a little to the side, so 

 as to rest directly on basal 7, and underlie radials 12 and 14 (E 

 and C). The analysis of the calyx of Cryptocrinus Icevis which 



* Op. cit. p. 687, tab. 113. fig. 94. 



t ' North American Geology and Palteontology,' 1889, p. 262. 

 ]. "The Structure, Classification, and Arrangement of American Palaeozoic 

 Crinoids into Families," Amer. Geologist, 1890, vol. vi. p. 351. 



§ " British Fossil Crinoids, II.," Ann. & Mag. Nat. Hist. 1890, vol. v. p. 382. 

 II Loc. cit. Taf. ii. fig. 5. 



