NO. 3544 SUBSPECIES OF CAMBARUS LONGULUS — JAMES 5 



with aa indistinct row of weak serrations; all surfaces with scattered, 

 deep punctations. Palm broad, with widely gapmg (in adults), 

 subcylindrical fingers which meet only at their tips; inner base of 

 immovable finger with tuft of plumose setae in immature animals, and, 

 except in upper James River, to some degree in older forms. Proxi- 

 momesial angle of inner margin of palm strongly hooked proximally, 

 forming, with carpus, a deep-curved acute angle (pi. 1mm: C) ; length 

 of inner margin of palm (pi. 1mm: A) at least twice that of distance 

 between spine of carpus and proximal extremity of inner margin of 

 palm when the chela is fully extended (pi. 3mm: B) (in well over 75 

 percent of examined specimens). Width of palm .53-1.0 (average 

 .80) times dactyl length; length of outer margin of chela 1.5-3.6 

 (average 2.7) times that of inner margin of palm and 1.0-2.6 (average 

 1.7) times greater than the length of dactyl. First pleopod of first- 

 form male reaches coxa of third pereiopod when abdomen is flexed. 

 (For detailed description of first pleopod of first-form male, see Hart, 

 1952, p. 47; Parish, 1948, figs. 2, 4.) 



Remarks.— Faxon (1898, p. 650) (1914, pp. 389, 424) lists as C. I, 

 longulus several collections which should be referred to C. I. chas- 

 modadylus or C. longulus longirostris ;Newcomhe (1929, maps 268, 278, 

 286) and Fleming (1938) repeat the errors of Faxon. All collections 

 erroneously recorded as C. I. longulus are hsted by me with their 

 proper designations in Mst I (p. 7). 



Of the three subspecies, C. I. longulus appears to be the most 

 variable. Although most populations possess a tuft of plumose 

 setae at the base of the immovable finger of the chelae, those of the 

 upper James drainage typically lack such a tuft. Ortmann (1931, 

 pp. 118-124) notes the absence of lateral spines on the carapace of 

 nine of his specimens of C. I. longulus. He was correct only with 

 respect to a minority of populations; most have spines. 



Some taxonomic characters, previously used by other investigators, 

 must be disregarded or used only in part. Size, although of interest, 

 gives Httle indication of subspecific variation; most C. I. longulus 

 are, on the average, smaller than C. longulus longirostris or C. I. 

 chasmodactylus ; the carapace length of the largest first-form male 

 C. I. longulus examined is 34 mm. and its hand length 29 mm. This 

 male is larger than some first-form males of C. longulus longirostris 

 and C. I. chasmodactylus: hence, size (sexually mature adults) as 

 a taxonomic criterion must be used in combination with other char- 

 acters. Color and color pattern of living specimens are sometimes 

 useful in separating populations of C. I. longulus (speckled green 

 to orange versus concolorous blue greens and browns). Color pat- 

 tern is of slight intersubspecific value in that neither of the other 



