H. L. Hawkins — Morphology of Echinoidea. 443 



in large, though peculiar, development, has an undoubtedly oblique 

 peristome. In C. rhotomagensis, C. castanea, and C. subrotimdus this 

 character is quite marked ; it is less clear in C. albogalerus, but among 

 hundreds of specimens (of very varying shapes and sizes) that have 

 passed through my hands, every one has shown appreciable ellipticity 

 of the peristome. Echinoneus, in spite of the unfortunate name of its 

 genotype, has a strongly oblique peristome when adult. As far as 

 my experience goes, I am convinced that the "obliquity" or 

 "symmetry" of the peristome are merely relative in all the forms 

 usually comprised under the three names in the title. Lambert says 

 of P. petrocoriensis that its peristome " est en effet semblable a celui 

 des Conulus'''' — that is to say, it must be slightly oblique. If this i& 

 so, why should not Nucleolites ovulum, Lam., whose peristome is 

 slightly more oblique, be admitted into the genus? A yet more 

 marked obliquity characterizes the peristome of P. desmoulinsi, 

 d'Arch., but the difference is merely one of degree. The species last 

 named has a " systeme buccal interne" sufficiently "analogue a, celui 

 de " Conulus. I have not succeeded in dissecting out the girdle of 

 P. desmoulinsi, but by sectioning a test and its infilling matrix I have 

 determined that a raised and thickened rim surrounds the peristome 

 within. It has yet to be suggested that Conulus subrotundus and 

 C. albogalerus are not congeneric, but I have studied undoubted 

 examples of the former species in which the peristome was no less 

 oblique than it is in P. desmoulinsi, or, for that matter, in Trematopygus. 

 But if these two common species of Conulus are to be allowed to share 

 the same generic name, it seems illogical to attempt a separation of 

 the various species commonly called Pyrina on the ground of variable 

 obliquity of the peristome. That there may be other features that 

 would warrant the generic distinction of some of the species I am 

 prepared to admit, but Pseudopyrina seems to me to be based on false 

 premisses and so unacceptable. 



Globator, with type G. nucleus, Agassiz, included a series of forms 

 (with relatively pronounced peristomial obliquity) that may be 

 roughly described as "roundish Pyrinas'". G. nucleus is always a 

 little longer than broad, and a little less in height, but it is at least as 

 "regular" in shape as, say, Holectypus depressus or many forms of 

 Conulus subrotundtis. Certainly the difference in ambital outline 

 between Globator aud such a species as Pyrina desmoulinsi is very 

 marked, but all possible gradations link the two species, and the 

 species of Conulus vary but very little less in this respect. If the 

 globular character can be shown to have any phyletic, or even 

 strati graphic, meaning, Globator might be recognized as a valid genus, 

 but I am unaware that either quality has been demonstrated. 



As a consequence of the arguments given above, I prefer to follow 

 the old-fashioned, and apparently natural, use of the name Pyrina, 

 and to include in it as unnecessary or unsubstantiated groups the 

 two so-called genera Globator and Pseudopyrina. In passing, it seems 

 advisable to draw attention to a statement made by Lambert (I.e., 

 pp. 142-3) concerning Pyrina houzeaui, Cotteau. " In spite of the 

 presence in this circular species of a small, imperforate, fifth genital," 

 Lambert does not feel justified in separating it from Globator (i.e. 



