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PROCEEDINGS OF THE NATIONAL MUSEUM 



is in the proximal portion of the appendage. The American species 

 (including the subadult male) agree with one another in having two 

 lobes on the basal division, and also have a seta at the base of the 

 first lobe, not shown in either typica or canalis. 



Table 1, — Seiation of inaxillule in Ridgewayia 

 (Unknown for R. canalis, and Ridgewayia sp. from Madras) 



Legs 1-4: Complete information on the armature of legs 1-4 is 

 available for only the American species. It is alike in the Tortugas 

 species, including the subadult male of unknown identity (Ridgewayia 

 sp., Tortugas). Since the specific pattern is probably established by 

 this stage, it is included in the summaries of armature. Esterly (1911) 

 illustrated only leg 1 of marki, but he gave a table of setation which, 

 if correct, shows that the number of setae on the endopods of legs 3 

 and 4 differ from the Tortugas species. Information is incomplete 

 for the other species, being known for only some of the legs of a single 

 sex of each species. No summary of setation is given in the text, and 

 only some of the legs are illustrated. These are: 



typica 9 



canalis cf 



sp. (Madras) cT 



legs 1, 2, 4 

 legs 1, 2 

 legl 



An inner seta is known to be present on basipod segment 2 of 

 leg 1 in all the species; so far as known, it is absent on all the other 

 legs, but the information available in the literature is complete only 

 for the American species. The same incompleteness of information 

 applies to the inner seta of the first basipod segment. The presence 

 or absence of this seta may be a basic character on all taxonomic levels 

 in calanoid copepods, and it is important that it be accurately deter- 

 mined for every leg of each species. As now recorded in the literature 

 the inner seta of basipod 1 is as follows (-}- present; — absent; ? un- 

 known) : 



