256 



K. NAKAZAWA : 



five pairs of legs preceding the last slender ; their propodite 

 indistinctly segmented into 3 joints in the distal parts, each of the 

 joints armed with two remarkably long spines ; meropoditc shorter than 

 carpopodite. All exopods of thoracic limbs well developed ; outer 

 distal corner of their large first joint rounded and spineless. Last pair 

 of legs markedly reduced, papilliform and one-jointed in both sexes. 

 Marsupium composed of three pairs of lamellae springing from bases 

 of three posterior thoracic limbs. Pleopods of male, telson and uropod 

 just as decribed by Hansen. Body 14 mm. in average length. 

 Locality. Port Shimizu (Suruga Bay). 



Notes. — The original description of the species by Hansen in "The Schizopoda of the 

 Siboga Expedition " was drawn up from a single male individual and is therefore 

 necessarily incomplete. The diagnosis I have given above has been prepared after a 

 study of numerous well preserved specimens of both sexes. 



Genus Siriella Dana, 1852. 



11. Siriella watasei n. sp. 

 Plate VIII., figs. 8, 36. 



Diagnosis. Carapace with acute rostrum (fig. 8). Eye large, 



globose. Inner flagellum of antennule dilated at base. Antennal 

 scale about four times as long as broad in the broadest part, scarcely 

 reaching to tip of antennular peduncle. Posterior six pairs of legs 

 rather slender ; carpopodite strongly developed and longer than 

 meropoditc ; propodite segmented into two joints, the distal joint about 

 twice as long as the proximal ; dactylopodite remarkably long and 

 rather straight ; last pair of legs much shorter than preceding five 

 pairs ; exopodite in anterior seven pairs of thoracic limbs with the 

 first joint pointed at distal outer corner, but that of the last pair rounded 

 at the same part. All pleopods of male like same of Siriella vulgaris 

 Hansen 1910. Telson (fig. 36) shorter than three times its breadth at 

 base, somewhat constricted near base ; its lateral margin anterior to 



