86 UNITED STATES NATIONAL MUSEUM BULLETIN 296 



and proceeding posteriorly. Details of the rest of the mantle excepting 

 the aperture are lost (see fig. 20). 



The mantle aperture is characteristic of the species. A pair of horn- 

 like projections arise near the middle of the aperture and curve 

 slightly forward near the tips. They are armed on both sides with 

 several strong simple or bifid teeth, and many hairs. 



The pair of strongly chitinized opercular plates between these 

 horns and the attachment knob are each equipped with a row of 

 bifid teeth and hairs, terminating at the attachment end in a low 

 knob bearing two strong teeth and many hairs. The arching aperture 

 ventral to the horns bears several smaller bifid teeth and a well- 

 developed comb collar. The inside wall of the mantle is strongly 

 equipped with hairs in the ventral region. 



No orificial knob or attachment knob remained, and cannot be 

 commented upon. 



The head and mouthparts appear essentially as described by 

 Utinomi, and will not be discussed here. 



The mouth cirri were damaged, but did not differ noticeably from 

 those described by Utinomi. 



The terminal cirri number four pairs, without a caudal appendage. 

 They are biramous and multisegmented, on a two-segmented protopod. 

 The protopod had oblique sutures, and the two segments are essentially 

 of the same length, unlike those described by Utinomi. The inner 

 surface of the protopods are equipped with setae. 



The segmentation count could be estimated at about 21 for the 

 shortest, the anterior ramus of the first terminal c'rrus, and 45 for the 

 rest, with a little variation. This number is higher than average, but 

 I did not experience as much difl&culty as described by Utinomi re- 

 garding the obscured segmentation in the central areas of the cirri. 



The setation differs from that described by Utinomi. Most rami 

 clearly showed a single seta at the distal angle of every two or three 

 segments on the outer curvature, of about one and a half times the 

 segment length. On the inner curvatiu-e each segment bore a pair of 

 setae on the distal angle about three times the segment length and a 

 pair in the middle of the segment about two and a half times the seg- 

 ment length. 



The cyprid : The presence of cyprid larvae within the mantle cavity 

 indicates that the larvae are retained to this stage in this species. 

 The cyprids had been boiled in KOH but still differences from other 

 species of the order were noted. 



No cyprid or naupliar eyes were distinguished. No detailed orna- 

 mentation of the carapace was seen. 



