NEW MARINE ISOPODS MENZIES 139 



wanting at the lateral lappets of the three anterior thoracic segments 

 . . . ," and of lanira maculosa Leach, the genotype of lanira, he writes, 

 "Epimeral plates developed at all thoracic segments." Such differ- 

 ences, in my opinion, certainly separate the two genera and in a 

 very natural way, especially when they are reinforced by other 

 morphological evidence. The male jfirst pleopods of lolella lacinata 

 (G. O. Sars) differ considerably from those of lanira maxmlosa Leach. 

 Since the structure of the male first pleopods of lolella spinosa 

 (Harger) and /. speciosa Bovallius is not known, I cannot be certain 

 that they are structurally similar to those of lolella lacinata; however, 

 the probability is good that they are similar. /. maculosa and its 

 related species /. alta and /. tricornis lack elongate, pointed, postero- 

 lateral telsonic lappets, with structures as well developed on lolella 

 speciosa^ I. spinosa^ and /. lacinata. I believe that here, then, are 

 other structural features separating the two groups of species. The 

 total of the differences, in my opinion, makes it necessary that the 

 groups of species as typified by lanira maculosa^ on the one hand, 

 and lolella speciosa^ on the other hand, be generically separated from 

 one another. The other problem exists, however ; if lolella speciosa is 

 a synonym of lolella spinosa, as Hansen asserts, then a genotype should 

 be selected for the species resembling /. speciosa. Since I cannot at 

 present settle the question with certainty, I arbitrarily accept Richard- 

 son's statement that the species in question are distinct from one 

 another. Such an acceptance, with due regard to Dr. Hansen, does, 

 of course, permit less change in the existing nomenclature and for 

 that reason appears to be the more desirable alternative. 



Group MUNNINI Hansen, 1916 



Subgroup Pleurogonhni ' Nordenstam, 1933 



Genus PLEUROGONIUM G. O. Sars 



PLEUROGONIUM CALIFORNIENSE, new species 

 Figures 25, 26 



Holotype. — Male, length 1.25 mm., width at widest part of second 

 peraeon somite 0.8 mm. 



Allotype. — Length 1.1 mm., width 0.6 mm. 



Diagnosis. — First peraeon somite exceeding twice the length of sec- 

 ond, posterolateral edges evenly curved, lacking spines ; anterolateral 

 angles each with a large anterolaterally directed spine. Epimeral 

 spines of second to sixth somites located at posterior angle of the 

 epimeral plates. Pleotelson with a distinct constriction at anterior 

 end and with smooth lateral borders beset Avith a few small setae. 



« Considered by Nordenstam, p. 199, to be a subgroup of Ilansen's Munnini. 



