648 PROCEEDINGS OF TEE NATIONAL MUSEUM. vol.53. 



Unguiculus untoothed, shorter than, or longer than, the unguis, 

 narrowly lamellate proximally, gradually tapering or attenuating 

 distally, tuberculate basally. Fourth and fifth abdominal segments 

 each with 2 + 2 pseudocelli, in obhque pairs. Anal spines (figs. 71, 

 72) two, less than half as long as hind ungues, almost straight, 

 separated basally, with papillae reduced i-o rings. Clothing (figs. 

 73, 74) of dense short curving setae, with occasional long stiff setae. 

 Cuticular tubercles of moderate size (fig. 75). Maximum length, 

 4 mm. 



I have here improved my original diagnosis of ttiis species by the 

 addition of a more precise description of the antennal sense organ 

 and by a correction of my former statement in regard to the pseudo- 

 celli. Almost all the structures that I described as pseudocelli are 

 in reahty cuticular pits that form the sockets of exceptionally large 

 setae, and these sockets can be distinguished by their structure from 

 pseudocelU by means of high magnification. Most of the setae were 

 missing in my specimens, but the occasional setae that remained in 

 place were sufficient in number to enable me to reconstruct the 

 arrangement of setae as given in figure 7. 



The cotypes were collected by Prof. Trevor Kincaid, of the Harri- 

 man Alaska Expedition, from whom I received a few additional 

 specimens after the description was pubhshed. 



Seldovia, Cook Inlet, July, under stones at tide mark (No. 62). 

 Cook Inlet (No. 60). St. Paul Island, Bering Sea, August 1. 

 Unalaska, September, beneath stones covered with barnacles. 



Cotypes.— C&t. No. 5436, U.S.N.M. 



ONYCfflUEUS RAMOSUS, new species. 



Plate 69, fig. 8; plate 76, figs. 76, 77; plate 77, figs. 78-82. 



White. Postantennal organs (fig. 76) each with about 13 many- 

 lobed tubercles, of the Jtmetarius type. PseudocelU behind the 

 antennal bases 2 + 2, with wide ringlike borders (fig. 77), i^jitennae 

 shorter than the head. Sense organ of third antennal segment (fig. 

 78) with four papillae, three guard setae, a pair of sense rods and 

 two capitate coarsely tuberculate sense clubs. Dorsal pseudocelli 

 of body (fig. 8): 0, 1 + 1, 1 + 1, 1 + 1, 0, 0, 2 + 2, 2+2, 0; those of 

 the fourth and fifth abdominal segments being in obhque pairs. 

 Lateral and ventral pseudocelli absent. Unguis (fig. 79) stout, 

 curving, untoothed, Unguiculus gradually tapering from base to 

 apex, extending half as far as the unguis. Anal spines (fig. 80) two, 

 half as long as hind ungues, arcuate, on low contiguous papillae. 

 Clothing (fig. 81) of sparse, short, stiff setae and a few minute curv- 

 ing setae. Cuticular tubercles minute (fig. 82). Length, 1.3 mm,' 



This is the only one of our known species which has, at the same 

 time, branched postantennal tubercles of the fimetarius type and 



