174 PROCEEDINGS OF THE NATIONAL MUSEUM vol. los 



3. Middle caudal setae jointed at bases; leg 5 female, endopod 2, first inner seta 



placed near the proximal third (equaling about 3G percent of total length of 

 inner margin) ; leg 5 male, left endopod with a proximal, inner, movable 



process about as long as endopod R. gracilis, new species 



Middle caudal setae not jointed at bases; leg 5 female, this seta placed below 

 the proximal third (at about 42-44 percent of margin) ; leg 6 male, left 

 endopod unarmed 4 



4. Antennules, female and left male, 26-segmented; leg 4, endopod segment 2 



with 2 inner setae, segment 3 with 7 setae; leg 5 male, left exopod 2, outer 

 spine longer than its segment, reaching about to same point as longest 



apical 'process R. shoemakeri, new species 



Antennules, female and left male, 25-segmented; leg 4, endopod 2 with 1 

 inner seta, segment 3 with 6 setae; leg 5 male, left exopod 2, outer spine 

 shorter than its segment, reaching only to about middle of extended apical 

 membranes and processes R. marki 



Systematic position 



Ridgewayia (as represented by the female of R. typica) was referred 

 to the Calanidae by Thompson and Scott (1903) on the basis of the 

 resemblances of the cephalic appendages and legs 1-4. The lack of 

 agreement in the fifth legs was noted. As now known, the highly 

 modified fifth legs of both sexes and the geniculate antcnimle exclude 

 the genus from the Calanidae, but Thompson and Scott are correct 

 in then' implication that the unreduced, simply modified oral append- 

 ages and the first four pairs of legs are essentially primitive in structure. 



In his comments on Lampoidopus marki, Esterly (1911) did not place 

 the genus systematically. 



Gurney (1927) doubtfully referred Suezia canalis to the Pseudo- 

 cyclopidae because of its "general resemblance" to Pseudocy clops. He 

 pointed out, however, that canalis differs "very materially from 

 Pseudocyclops" but that he felt that "it must cither be included in the 

 Pseudocyclopidae or have a new family instituted for its reception," 

 a course "hardly justified without more complete knowledge of the two 

 sexes." Sewell (1932) and Kj-ishnaswamy (1953) have listed Suezia 

 in the Pseudocyclopidae without comment. 



The demonstrated relationship of the species considered herein 

 makes it possible to evaluate more critically their possible relationship 

 to the Pseudocyclopidae. There is some merit in Gurney's sugges- 

 tion, though the strongest resemblances between Ridgewayia and 

 Pseudocy clops, the only known genus of the family, are the superficial 

 ones of body form and habitat. Both have the stout body that is 

 seemingly characteristic of ex'tremcly littoral and bottom-living 

 calanoids. The segmentation of the body (including the reduced 

 anal segment), the caudal setae, and the large, unfilamented rostrum 



