646 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



vol. 38. 



Fig. 2.— Scyracepon HA 



"WAIIENSIS. MAXILLIPED. 



liped on the ventral side of the frontal border of the head; the 

 endopodite is triangular. 



All seven thoracic segments are distinct and 

 subequal in length. There is a tendency in 

 all except the first (most marked in the last 

 four) to be produced into a dorsal median 

 boss. This boss is most conspicuous in the 

 seventh segment and takes the form of a 

 strong hook-shaped prominence. The epimera 

 of the first four segments are conspicuous on 

 the anterior portion of the lateral margins. 

 Ovarian bosses are present on the first four 

 segments. The lateral margins of the last three 

 segments are concealed by the overlapping 

 elongated, anteriorly directed "lames pleu- 

 rales" of the abdominal segments. 

 The six abdominal segments are distinctly separated on the dor- 

 sal side. Each of the first five segments is 

 provided on either side with two elongate, 

 fringed appendages and a small sac-like body 

 on the ventral side at the base of the in- 

 ferior appendage. The superior elongate ap- 

 pendage on either side of each segment is the 

 "lame pleurale" of the segment, and these 

 decrease in size from the first to the fifth 

 segment, the first being extremely long, the 

 fifth quite small. The inferior elongated 

 blanches are the outer branches of the ple- 



opoda and resemble the 

 "lames pleurales." They 

 also decrease in size from 

 the first to the fifth seg- 

 ments. The inner branches 



of the pleopoda are five pairs of small sac-like 

 bodies, a pair for each segment on the ventral 

 side of the body, inconspicuous, forming two 

 converging longitudinal rows. 



The uropoda are a pair of elongated append- 

 ages attached to the sixth abdominal segment 

 and resembling the "lames pleurales" and the 

 outer branches of the pleopoda. 



There are seven pairs of small, feeble, pre- 

 hensile legs. There are five pairs of incuba- 

 tory plates which overlap in the middle of the 

 ventral side, completely inclosing the incubatory pouch. The distal 

 segment of the first pair is somewhat produced at the inner posterior 



Fig. :i. —Scyracepon iiawaii- 

 knsis. Mandible. 



Fig. 4.— Scvracepon ha- 

 WXHENSIS. First la- 

 mella of MARsri'iiM. 



