442 H. L. Hawkins — Morphology of Echinoidea. 



II. — Morphological Studies on the Echinoidea Holectxpoida 



AND THEIR ALLIES. 



By Herbert L. Hawkins, M.Sc, F.G.S., Lecturer in Geologj'-, University 

 College, Reading. 



IX. — Pyeina, Conulus, and Ecbinoneus. 

 TI1HE three genera (or generic terms) that serve for the title of this 

 J_ paper comprise a series of Cretaceous and Tertiary Echinoids 

 which are morphologically similar, and, in consequence, systematically 

 chaotic. Although the time is not yet ripe for an attempt to 

 disentangle the nomenclature of the various genera and species from 

 the knot in which it is involved (a condition not to be wondered at 

 in view of the early description and variable qualities of the forms), 

 it seems desirable to publish the following comments on the group, 

 making use of current names for the examples quoted. Pyrina,, 

 Desmoulins, as Lambert 1 has shown, is typified by P. petrocoriensis, 

 Desm., a species that might well pass for a young member of the 

 Conulus series. Conulus, Leske, has for genotype C. albogalerus, Leske, 

 and the forms to which that name is usually applied in this 

 country seem sufficiently like the original figure to pass muster. The 

 genotype of Echinoneus is of course E. cyclostomus, Leske, and there 

 has never been serious confusion as to the application of the generic 

 name. 



Under the name Galerites, Lamarck, Conulus became extended 

 to cover practically all the Holectypoida, and to include considerable 

 numbers of Clypeastrids and Echinolampids ; but the original type 

 has always been correctly placed, either under one of the two fore- 

 going names or that of Echinoconus. Pyrina was more than usually 

 unfortunate in the series of species included in it by its author. Of 

 the seven species cited by Desmoulins, P. petrocoriensis is the only 

 one that is either recognizable or conformable to the diagnosis, although 

 another (JYucleolites ovultwi, Lamarck)is almost, if not quite, admissible. 

 The long rejected Globator, Agassiz, 1840, has been revived (with 

 subgeneric rank) by Lambert (I.e.), and the latter author has proposed 

 the name Psendopyrina for the large number of more or less ovoid 

 Echinoids that have usually been placed in Pyrina. Before proceeding 

 to analyse the morphological qualities of the genera, a brief comment 

 on this proposed taxonomy is necessary. 



Lambert (I.e., p. 141) shows that Desmoulins, in founding the genus 

 Pyrina, twice emphasized the "symmetrical" character of the 

 peristome, and even proposed to exclude Nucleolites ovulum, Lam., 

 because of the slight obliquity of the peristome in that species. 

 Further, Pyrina had a perignathic girdle (" systeme buccal interne ") 

 analogous to that of Galerites ( Conulus). It may be remarked that 

 in Desmoulins' time, and for long afterwards, the belief was always 

 maintained that the possession of masticatory apparatus (including the 

 perignathic girdle) was restricted to Echinoids with " symmetrical" 

 (i.e. circular, pentagonal, or decagonal) peristomes. Unfortunately 

 for this belief, however, Conulus itself , which has a perignathic girdle 



1 ' ' Etude, sur les Echinides cretaces de Rennes-les-Bains et des Corbieres ": 

 Bull. Soc. Etudes Sci. Aude, vol. xxii, pp. 66-183, pis. i-iii, 1911. 



