202 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 18 



Uropod 2 : upper edge of peduncle with 3-5 stout spines, inner ramus 

 with or without a marginal spine; apices of rami with small, often dif- 

 ficult to see, submerged spines. , 



Uropod 3 : inner ramus about one fourth as long as outer or as much 

 as one third long; article 2 of outer ramus about one third as long as 

 article 1 or as little as one sixth as long. 



Telson slender, apices acute or slightly rounded, each lateral notch 

 with 2 setae. 



Third epimeron: posterior edge straight, lower corner scarcely pro- 

 duced, setae sparse or absent on posterior edge. 



Male. — Sexual dimorphism typical. 



Holotype. — AHF No. 534, female, 3.2 mm. 



Type locality. — Station 2310-53, near Long Beach Breakwater, Cali- 

 fornia, 33-40-00 N, 118-10-00 W, 15 fms, sandy mud, May 16, 1953. 



Remarks. — Small specimens from Station 2311-53 measuring about 

 2 mpi in length have only 2 teeth on article 2 of peraeopod 5. 



This species bears the name variatus due to the rather pronounced 

 variations encountered. Thus, the epistome may vary from long to of 

 medium length; peraeopod 5 may have three, four, or five teeth on the 

 posterior edge of article 2 ; the teeth may be short, medium sized, or long; 

 the presence or absence of spines on the first two uropodal rami occurs 

 but the variation apparently bears no relationship to sexual maturity, 

 although some correlation with size occurs. Specimens appearing to be 

 in the same stage of development regarding setosity and spinosity occur 

 at different stations but are different in size, indicating possible effects 

 of available food or crowding, thus resulting in different rates of matura- 

 tion. Since most of the stations examined are in shallow waters, there is 

 no correlation of size to depth of habitat. 



Table 3 is a compilation of some variable features in the species. It 

 must be noticed that specimens from Stations 2505-53, 2607-54, and 

 2646-54 have fourth peraeopods which are similar to those of P. fatigans, 

 n. sp. The similarity is based on stoutness of article 5 in P. fatigans. See 

 the latter species for a discussion of the close relationships of the two 

 animals. 



Material examined. — 429 specimens at 72 stations. 



Distribution. — Southern California coastal and insular shelves, 5 to 

 60 fms. Eighty percent of the records are shallower than 20 fms. 



