﻿MARINE ASELLOTE ISOPODS — MENZIES 135 



dorsal view on at least peraeon somites 2 to 7. Pleon composed of 

 two somites. Uropods of variable length. Maxillipedal palp con- 

 sisting of five segments, second and third segments expanded, being 

 much wider than endognath. Maxilliped with two coupling hooks. 

 Male first pleopods laterally expanded at apex. Female operculum 

 with distal margin blunt or slightly concave. Dactyl of first peraeo- 

 pods biunguiculate ; those of peraeopods 2-7 all triunguiculate. Pro- 

 podus of male first peraeopod smooth, lacking a series of serrations 

 on inferior margin but usually bearing a variable number of 2-pointed 

 setae. Mandibular molar process expanded at tip, apex truncate; 

 second article of palp bearing two long, fairly straight denticulate 

 setae, between which is a smaller strongly curved denticulate seta. 

 In adult males the first pair of peraeopods are often almost as long 

 as the body when expanded. First antenna with a 4-jointed peduncle. 

 Second antenna with a G-jointed peduncle bearing an obvious squama 

 on the lateral border of the third joint. 



Remarks. — The diagnosis given by G. O. Sars (1897-99, p. 102) 

 for this genus appears incorrect in one important respect : the dactyls 

 of the 2 to 7 peraeopods are triunguiculate and not biunguiculate, as 

 one would gather from that diagnosis. 



The species belonging to this genus that I have seen differ from one 

 another only in a few respects. Some have spinelike serrations on 

 the lateral edges of the pleotelson, while in others those borders are 

 smooth. In certain species the general shape and relative length of 

 the uropods are distinctive. The most reliable diagnostic features 

 seem to be present on the male first pleopod, particularly at the lateral 

 apex. Thus, in some the apex is entire, while in others it bifurcates; 

 in some it is directed laterally, and in others it is directed abruptly 

 posteriorly. Only a combination of the several features mentioned 

 above provides a satisfactory means of separating the species. 



From the northern California coast the detection of seven species 

 has been possible. Previously only one valid species was known from 

 that area. The species described by Richardson as Janiropsis cali- 

 fornica probably belongs to lais and not to laniropsis. One of the 

 species, laniropsis analoga. is so very closely related to the genotype 

 that it may later be found identical with that species. However, since 

 real differences are apparent it seems best to keep the forms separate, 

 at least for the present. 



Eupraxia Gurjanova's Janiropsis derjugini is believed to be only a 

 subspecies of Richardson's Janiropsis kincaidi and is herein called 

 laniropsis kincaidi derjugini Gurjanova. The species /. pugettensis 

 Hatch (1947, p. 172) is a synonym of /. k. kincaidi Richardson, as 

 indicated by a comparison of paratypes of that species with cotypes 

 cf Richardson's species. 



