140 PROCEEDINGS OF THE NATIONAL MUSEUM vol.ios 



in the Calanoida. It remains for future studies and accurate, detailed 

 knowledge of both sexes of all the species to determine whether we 

 are dealing here with more than one genus. Most of the differences 

 that have been found to exist on the basis of literature, need, in my 

 opinion, to be verified by further examination of specimens. 



The determination of the proper generic status of all these species 

 is primarily dependent upon knowledge of the male of typica. Its 

 discovery should serve to differentiate Ridgewayia and Lampoidopus 

 if they are truly generically distinct. It may or may not solve the 

 status of Suezia canalis, which may be further dependent upon knowl- 

 edge of the female and reexamination of the male. The two new 

 Tortugas species would be referable to Lampoidopus if it is established 

 as a separate genus. 



Subclass COPEPODA 



Order CALANOIDA 



Genus Ridgewayia Thompson and A. Scott 



Ridgewayia Thompson and A. Scott, 1903, p. 245. 

 Lampoidopus Esterly, 1911, p. 219, new synonym. 

 Suezia Gurney, 1927, p. 457, new synonym. 



Diagnosis (emended): Species small, approximate range of length 

 between 0.6 and 1.0 mm. 



Metasome stout, 5-6-segmented, the somite of leg 1 distinctly or 

 indistinctly separated, or fused with cephalic segment, 



Urosome less than half the length of metasome, 3^-segmented in 

 female; if present, the fourth segment reduced to width of caudal 

 rami; 4-5-segmented in male, fifth segment, if present, reduced as in 

 female. Paired genital openings of female closely set (known only 

 for the new species) . Caudal rami longer than wide, with foiu- terminal 

 setae longer than rami, of these the second from the inner the longest 

 (an outer spine also present in marki and in the new species) . 



Rostrum down turned, broad at base, rounded or pointed distally; 

 filaments lacking. 



Cephalic appendages all of primitive calanoid type, without re- 

 duction, excessive modification, or sexual differentiation. 



Antennule reaching from near end of metasome to caudal rami; 

 25-26-segmented in female (21-22-segmented in canalisi); the three 

 apical segments elongate. Left antennule male like that of female 

 (where known); the right of 21-24 segments, with a moderately de- 

 veloped geniculation, segmentation beyond this specialized joint 

 varying from three to four segments (geniculation reportedly not 

 present in canalis and Ridgewayia sp. (Madras)). 



