104 HAWAIIAN AND OTHER PACIFIC ECHINI. 



preoccupied. When a complete revision of all the known forms, both living 

 and fossil is made, it is probable that a more natural grouping, in accordance 

 with some of Hawkins' suggestions, will be possible. Most of the living genera 

 have the periproct in a more or less marked depression above the ambitus, 

 but the most highly specialized forms have it distinctly on the oral surface. 

 The number of genital pores is probably 4 in mature specimens, and, except in 

 Neolampas, the individuals described as having only 2 or 3 such pores were 

 probably not fully adult. The pedicellariae are in no way distinctive but tri- 

 dentate, ophicephalous, and triphyllous occur in greater or less abundance, 

 though often one or the other of these forms seems to be lacking. As a rule 

 the pedicellariae are exceedingly small, and the triphyllous in particular are 

 hard to find. The miliary spines remind one of those found in the Laganidae, 

 as they usually have a more or less multiscalariform structure as in that family. 



The Recent species of this family are not numerous but their proper group- 

 ing in genera has caused some difficulty, in part due to the attempt to refer 

 certain species to genera based upon Fossil forms. This is well illustrated by 

 the species referred to Catopygus by A. Agassiz and by Studer. Duncan 

 recognized the fact that neither is strictly congeneric with the fossil forms of 

 that genus but in attempting to establish a subgenus (Studeria) for their benefit . 

 he unfortunately makes mention only of Laube's Tertiary C. elegans. Hence 

 that species necessarily becomes the type of Studeria. Now a careful compari- 

 son of C. elegans with Agassiz's and with Studer's species shows that it is not 

 congeneric with either. For Agassiz's Catopygus recens, I therefore propose 

 the generic name Hypselolampas (see p. 109). Studer's C. loveni is not closely 

 allied to H. recens, as it has no visible petals and the periproct is different. 

 Judging from the published figures it seems to be a Neolampas and I venture, 

 without having seen a specimen, to refer it to that genus. 



Bell's Nucleolites occidentalis has also given rise to some difficulties. As 

 Bell does not compare his specimen with Lamarck's Cassidulus cariboearum 

 and indeed does not mention that species or even the genus, it is not strange 

 that the fact has been hitherto overlooked that Bell's species is identical with 

 Lamarck's! Duncan established the subgenus Oligopodia for the Recent 

 species of Nucleolites but Hamann on accepting it as a genus restricted it to 

 the single species 0. epigonus, leaving Bell's species and recens Milne Edwards 

 in Nucleolites. As already stated Bell's species is not a Nucleolites at all (see 

 below under Rhyncholampas) while recens scorns to me too near to epigimus 

 to be placed in a separate genus. 



