76 UNITED STATES NATIONAL MUSEUM BULLETIN 296 



plumose with extremely fine hairs. The smaller posterior ramus is on 

 the inside of the larger anterior ramus in its attachment to the proto- 

 pod. Both rami are heavily bristled on the margins and on the inside 

 lateral surfaces. 



The three pairs of terminal cirri are biramous and multisegmented 

 (fig. 15f). The arrangement of setae is typical for the suborder: 

 a repetition of a distal long pair of setae (two to three and a half 

 times the length of the segments, grading from base to tip of cirrus), 

 and a central shorter pair (about the same length as the segment) 

 along the lesser ciu-vature of each segment, with a single seta (one to 

 two times the length of the segment) on every first to fifth article 

 along the greater curvature. The average numbers of segments per 

 bristle for each cirrus are as follows (one specimen): cirrus 2: 1.69; 

 3: 2.90; 4: 2.97. The protopods are two-segmented, with the proximal 

 segment much longer than the distal segment. The sutures between 

 segments slant obliquely. The inner surface of each protopod is 

 set with bristles. The average cirral count (of five specimens) with the 

 segments in the anterior (listed first) and posterior ramus of each 

 cirrus, are as follows: 2: 27.0, 37.0; 3: 40.5, 45.6; 4: 42.0, 44.8. 



The caudal appendages arise between and behind the last pair of 

 terminal cirri. They are uniramous and two-segmented, with usually 

 three terminal setae. The appendage itself is about half the length of 

 the basal segment of the protopod on the last terminal cirrus. 



There are no body processes of filamentary appendages. The thorax 

 possesses the usual fine striations. 



The male: The dwarf males attach to the female, especially on the 

 exuviae forming the horny disk. Females of adult size have from 

 zero (many females) to five (very few) males each. This is a lower 

 number than is typical for the order. 



The young male looks much like a cyprid larva. The swimming 

 appendages, caudal furca, paired cyprid and single naupliar eye, and 

 paired antennules are typical of the entire subclass. The distinct line 

 across the carapace near the posterior end, seemingly articulating a 

 posterior segment of the carapace, is not typical. Glandular cells 

 are found around the cirri and in several masses along the dorsal edge 

 of the carapace. Muscles are attached to the antennule bases. The 

 antennules have a distinct angle near their base, which is clearly 

 dimpled with heavy chitin. 



The mature male has an obvious cellular testis and a seminal 

 receptacle full of hair-like sperm, connected in turn to an annulated 

 penis whose termination and method of employment is obscure (fig. 

 15g). There seems to be a penis retractor muscle connected to one of 

 three lobes projecting from the main body of the male, with the testis 

 in another lobe; the third lobe bears a few cells which appear glandular. 



