PART 1 GARTH : PACIFIC OXYRHYNCHA 67 



Genus COLLODES Stimpson 



Microrhynchus Bell, 1835a, p. 88; type: M. gibbosus Bell, by subse- 

 quent designation of Miers (1879c, p. 651) ; 1836, p. 40. Dana, 

 1851b, p. 427. 

 Neorhynchus A. Milne Edwards, 1879, p. 186 (name substituted for 



Microrhynchus, preoccupied). 

 Collodes Stimpson, 1860b, p. 193; type: C. granosus Stimpson, by mono- 

 typy. A. Milne Edwards, 1878, p. 175. Miers, 1879c, p. 645. Al- 

 cock, 1895, p. 189. Rathbun, 1901, p. 55; 1925, p. 105. 

 Dasygyius Rathbun, 1897, p. 164 (name substituted for Neorhynchus, 

 preoccupied) ; 1925, p. 137. 



Type: Collodes granosus Stimpson, by monotypy. 

 Description: Carapace ovate-triangular. Rostrum short, entire, or 

 bifid with the lobes approximated. Eyes of moderate length, retractile 

 against a large, triangular postocular process separated from supraorbital 

 arch by a deep, open, marginal fissure. Basal antennal article narrow, 

 a little curved, anteriorly bidentate, one tooth placed behind the other, 

 movable part long, exposed. Merus of outer maxillipeds obcordate, 

 broad as ischium, deeply incised on distal margin, internal angle promi- 

 nent, acute. Chelipeds of moderate size. Ambulatory legs short, pre- 

 hensile, dactyli slender, equal in length to propodi, and retractile against 

 them. Abdomen of male with six, of female with five segments. (Stimp- 

 son, as modified by Alcock and by Rathbun) 



The present difficulty with respect to the two species originally 

 described by Bell as Microrhynchus gibbosus and M. depressus arises 

 not so much from the fact that they are not congeneric, as Bell supposed, 

 but that M. gibbosus, the species which on rediscovery allies itself with 

 members of the genus Collodes Stimpson, rather than Microrhynchus 

 depressus, the species that stands alone, was arbitrarily chosen by Miers 

 (1879c, p. 651) as the type of Bell's genus. Such a designation, once 

 made, is as binding on subsequent reviewers as if included in the original 

 description, according to Article 30 of the International Rules of Zoo- 

 logical Nomenclature, paragraphs f and g. Had Miers chosen M. de- 

 pressus as type instead, it might have been possible to preserve the name 

 Dasygyius Rathbun as the latest in a series of substitutions for Micro- 

 rhynchus Bell. Under the Rules, therefore, the present writer has no 

 option but to suppress Dasygyius Rathbun, 1897, in favor of the earlier 

 Collodes Stimpson, 1860, and to erect a new genus to accommodate 

 the otherwise nameless Microrhynchus depressus. A petition to the Inter- 

 national Commission on Zoological Nomenclature for a suspension of 



