A. E. 'Verrill — Study of the family Pectinidm. 55 



three genera : Amusium (type A. pleuronectes) ; Chlmnys (type = 

 C Islandica) / Pecten (type P. maximus, also dubius, tTacohma, etc.) 



He gave no diagnoses, but cited well known and figured species 

 as types, so that his meaning is clear. 



Schumacher, in 1817, undoubtedly ignorant of Bolten's work, again 

 divided Pecten. He restricted Pecten to the group called Chlamys 

 by Bolteu, and for the true Pecten he proposed the name Janira. 

 He used Atnusium for the same type as Bolten, and established 

 another good division under the name Pallium, for P. ^Mca Linne. 



The genus Am,usium was adopted by Bolten from Klein, and its 

 type has never been in doubt. 



The genus Chlamys of Bolten included a large majorit}^ of the 

 species included in the genus Pecten by Lamarck and most of the 

 conservative writers. The name was adopted by H. and A. Adams 

 for a small and ill-defined section of Pecten, while most of the more 

 typical forms cited by Bolten were retained in Pecten, so that Pecten 

 of H. and A. Adams (type, P. variiis) is practically the same as 

 Chlamys of Bolten. 



Fischer, 1887, adopted Chlamys, in its widest sense, to include the 

 greater part of the family PectinidcB, such groups as Pseudamusiiim, 

 Pallium, Lyropecten, Camptonectes, and several others, being 

 regarded as its subgenera or sections. But C. Islandica was cited 

 as the special type of the restricted group. 



Stoliczka, 1871, adopted Chlamys in a more restricted sense, with 

 C hifrons Lam. as the type. He followed H. and A. Adams in 

 adopting Pecten for a very large group, with P. varius Linne as the 

 type, while the true genus Pecten was called Vola (after Klein and 

 H. and A. Adams). It is singular, however, that none of those 

 writers who have adopted Klein's generic names have referred to the 

 fact that Klein himself placed the one-sided pectens in the first sec- 

 tion of his genus Pecten, and that his first " species " included 

 P. maximus/ On a subsequent page he gave Vola, with a brief 

 diagnosis, for a single species of the same group, evidently not real- 

 izing its close affinity to his typical Pecten. Thus Yola was a syn- 

 onym of Pecten even in the work of Klein ! 



2. ScABRiuscuL^. Nodosa (1 sp. ; P. nodosa). Squamatce (13 pp.; P. lyallium, 

 sulphtirea, porphyrea, aurantia, pusio, varia, Ungua-felis, incarnata, pseudamusmm, and 

 vitrea are identifiable.) 



PECTEN. 



(P. maxima, dubia, Joxohaa, pidus, ziczac.) 



AMUSIUM. 

 (P. pleuronectes, jap>onicum, LaurenUi.) 



