646 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



vol. 38. 



Fig. 2.— Scyracepon hawaiiensis. Maxil 



LIPED. 



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

 endopodite is triangular. 



All seven thoracic segments are distinct and snbequal in length. 

 There is a tendency in all except the first (most marked in the last 



four) to be produced into a dorsal me- 

 dian boss. This boss is most con- 

 spicuous 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 lat- 

 eral margins of the last three segments 

 are concealed by the overlapping elongated, anteriorly directed 

 "lames pleurales" of the abdominal segments. 



The six abdominal segments are distinctly separated on the dorsal 

 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 appendage on either side 

 of each segment is the "lame pleu- 

 rale" 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 branches are the outer branches of the 

 pleopoda and resemble the "lames pleurales." They also decrease in 

 size from the first to the fifth segments. 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, in- 

 conspicuous, forming two converging 

 longitudinal rows. 



The uropoda are a pair of elon- 

 gated appendages attached to the 

 sixth abdominal segment and resem- 

 bling the "lames pleurales" and the 

 outer branches of the pleopoda. 

 There are seven pairs of small, feeble, prehensile legs. There are 

 five pairs of incubatory 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. 3.— Scyracepon hawaiiensis. Mandible. 



Fig. 4. 



-Scyracepon hawaiiensis. 

 lamella of marsupium. 



First 



