4 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 23 



of individual opinion, and cannot be objectively defined ; the genus, 

 subgenus and subspecies are particularly arbitrary and subjective cate- 

 gories, the species considerably less so. The taxonomic procedures fol- 

 lowed in the paper are outlined below. 



Nomenclature: Problems concerning the validity of generic and 

 specific names have been resolved by strict observation of the Inter- 

 national Code of Zoological Nomenclature and the Opinions of the 

 International Commission on Zoological Nomenclature. Although logical 

 arguments against rigid application of the Law of Priority have been 

 frequently presented, order and unity in taxonomy can be maintained 

 only by strict compliance with the Law until it is officially modified. 



Genera: Unless otherwise indicated, all units were originally pro- 

 posed as genera. Synonyms which are also homonyms are preceded by 

 [non]. For each unit, including those synonymized, the type-species and 

 type locality are given. For the units regarded as valid, the original 

 diagnosis is given, an additional diagnosis by the present author, re- 

 marks, and a list of representative species. 



Species: The generic and specific names in synonymies are primarily 

 those necessary to illustrate the nomenclatural history of each species; 

 repetitions of the same combinations of names are cited only when an 

 author gave the first figures of a species or when he contributed further 

 geographical or geochronological data. Misidentifications or synonyms 

 which are also homonyms are preceded by [non]. For each species re- 

 garded as valid, the present location of the holotype is given, the type 

 locality, the original description, an additional description or descriptive 

 notes by the present author (except in a few cases), remarks, the known 

 geographical, geochronological and bathymetric ranges, ecological data, 

 and the Hancock expeditions stations at which the species was found. 



References: To ensure the accuracy of references cited, all but 

 four of the publications in which they originally appeared were examined 

 by Mrs. Dorothy M. Halmos, librarian for the Hancock Foundation, 

 or by the author. Most of the sources were in the Foundation library; 

 of the remainder, some were in the author's library, 12 were borrowed 

 from other libraries, and four volumes not available in this country were 

 examined by fellow workers abroad. The importance of verifying refer- 

 ences at their source is proven by the fact that a large number of those 

 cited in the literature were found to be erroneous in one or more respects. 

 In too many instances a slip of the pen or a typographical error was 

 accepted by subsequent authors who did not or could not examine the 

 original source, and thus the error was perpetuated. 



