407 



The fusion of pereon somites I and II is not complete: they are ven- 

 trally separated and the coxal plates of the corresponding pereopods are 

 also separated. All the coxal plates are short, narrow, and not touching 

 each other.The 2nd segment of the pereopods diverges from its distal 

 margin and not from the inner surface, as in most hyperiids. The pere- 

 opods are of the ambulatory type, differ little in length, and are absolutely 

 monotypic in structure: the segments are narrow, the 2nd and 5th seg- 

 ments are the longest, and the 6th segment in all pairs is shorter and 

 narrower than the 5th. 



The pleon is shorter than the pereon and the pleopods have a massive 

 base. The epimeral plates have rounded margins. The rami of uropods III 

 are attached to the basipodite and considerably separated from each other. 



Notes: Separation of the two undoubtedly closely related species of 

 Diarela is difficult since the charaters separating them fall in the range 

 of age and sex variation and possibly future investigation will show that 

 these two species are identical. 



Type species: Paraphronima californica Bovallius, 1885. 



KEY TO SPECIES OF GENUS DAIRELLA* 



1. Pereopods V slightly longer than pereopods FV, 2nd segment not 



longer than 5th. Rami of uropods III narrowly lanceolate 



1 . D. californica (Bov.). 



— Pereopods V noticeably longer than pereopods IV, 2nd segment 



much longer than 5th. Rami of uropods III broadly lanceolate 



2. D. latissima Bov. 



1. Dairella californica (Bovallius, 1885) (Fig. 176) 



Bovallius, 1885b: 11 {Paraphronima); 1887a: 24; 1889: 333. 



Length of females 9 mm. Male not known. 



The head is greatly bulged, appreciably elevated above the dorsal 

 line of the pereon, and equal in length to the first three pereon somites; its 

 height is slightly more than its length and the length and width identical. 

 The upper groups of ocelli are more numerous than the lower and are 

 dorsally separated by a broad space. Antennae I are more than half the 

 length of the head; the 1st segment of the peduncle is somewhat longer 

 than the next two together; the lone segment of the flagellum is finger- 

 shaped, twice longer than the peduncle, and medially densely pubescent 

 with setae. 



The pereon is slightly less than twice as long as the pleon; the 

 somites are low; the border between somites I and II is seen only 



* Changed from Russian text by authors — Eds. 



