54 A, E. Verrill — Study of the family Pectinklm. 



type-species wei'e given. There is, therefore, much diversity of 

 usage regarding their names and limits. The type-species of Pecten 

 itself has not yet been settled. The name is of very ancient origin. 

 It seems to have been first used, under the binomial system, by 

 Miiller in Prod. Zool. Dan., 1776, His first species was P. maxinnts 

 L. The same is true of DaCosta (1778), and Cuvier (1798). H. and 

 A. Adams cited Linne as authority for Pecten, with P. varius as 

 type, but I cannot find an}^ basis for so doing, for Linne never 

 adopted the genus. Fischer and others go back to ancient polyno- 

 mial writers for the name, but the works of sucb authors should have 

 no influence in determining priority of names under the binomial 

 system. 



The determination of the true type of Pecten depends upon what 

 rules of nomenclatui'e one adopts. If we follow the well known and 

 important rule that prioi'ity of binomial names does not apply to 

 the names in works earlier than the 10th edition of Linnaeus, we 

 must treat the names given by Klein as dating only from the time 

 when first adopted by a binomial writer. Much of the confusion 

 and disagreement in the nomenclature of authors is due to the neg- 

 lect of this rule by several prominent writers. By the application of 

 the rule much confusion may be avoided in the future. Klein, him- 

 self, merely adopted the name Pecten, from much earlier writers, in 

 a somewhat restricted or modified sense. His first division of Pecten 

 was made for the one-sided species, and the first species in his list 

 was P. maximus. On a subsequent page, however, he gave the 

 name Vola to another species of the same group. The latter, 

 judged by his own diagnosis and figure, should have been placed in 

 his first section of Pecten. 



The author who first subdivided an old genus has the right, under 

 the rules generally adopted, to assign the old name to either division 

 unless there be very positive evidence that a special type had pre- 

 viously been designated by its originator. 



The first binomial writer to subdivide Pecten and restrict the 

 name to a particular type was Bolten, 1798.' He divided it into 



' As Bolten's work is rare. I here reproduce aa extract from it relating to the 

 Pectinidaj, furnished to me by Dr. Dall. " Bolten in 1798 worked in a very rational 

 manner. He divided the old genus Pecten as follows : " 



CHLAMYS. 

 1. Glabr.e. Striatce (two names of species, both = P. islandicus). * * Sukatm 

 (10 species; citrina, glabra, tranqueharica, cjibha, radula). Plicatoe (15 sp. ; cornea, 

 cror.ea, ruhiginosa are identifiable). 



