GAMMARIDEAN AMPHIPODA 



63 



mens combine the following characters : coxa G of minuta and innguis^ 

 gnathopod 1 (not counting the coxa) of some forms of minuta^ lefi- 

 dula^ ruiinusGula^ epistome of pingiois (but with slight modification), 

 coxa 1 of pinguis, minuscula, intermedia; epimeron 3 of pinguls, lepi- 

 dida, minuscida; eyes of 7iunuscula (?), uropod 3 of pinguis (but 

 apparently no others if drawn correctly) and gnathopod 2 of one 

 form of 0. minuta. 



Table 3. — Variation in six characters of 11 forms of 5 closely related species of 

 Orchomcne (Symbols: + = yes; 0=no; +0, 0+ ^intermediate conditions; 

 ?= questionable) . 



Species names 



minuta [Gurjanova, 1962, fig. 41] 



minuta [Gurjanova, 1962, fig. 42] 



mmula [Gurjanova, 1962, fig. 43] 



lepidula Gurjanova, 1962, fig. 44 



intermedia Giu-janova, 1962, fig. 4o_ 

 intermedia Gurjanova, 1962, fig. 46. 

 minuscula Gurjanova, 1962, fig. 47. 



pinguis [Gurjanova, 1962, fig. 48] 



pinguis [Gurjanova, 1962, fig. 49] __ 



pinguis [Woods Hole, Mass.] 



pinguis [Santa Monica Bay, Calif.] _ 



In two characters, the Californian population resembles that from 

 Norway (Sars, 1895) more than it does that from Woods Hole. These 

 characters are the elongated pereopods 3-5 and the form of the pre- 

 buccal structure. 



Two collections of O. pinguis from the northwestern Pacific illus- 

 trated by Gurjanova (1962) differ from each other, from Sars' dra wr- 

 ings and from "Woods Hole specimens. Both of Gurjanova's illus- 

 trated specimens are females but uropod 3 differs strikingly, one of 

 them being more spinose and with a slightly longer inner ramus than 

 the other. One of the sixth coxal lobes is sharply quadrate, the other 



