370 CRAYFISHES. 



Cambarus viae-viridis, sp. nov. 

 Plate 6. 



Male, form I : — Rostrum long, triangular, plane above, margins raised so 

 as to form a sharp rim, destitute of lateral spines or angles; acumen strongly 

 deflexed, not clearly defined; a shallow depression or foveola at the posterior 

 end of the rostrum. Carapace punctate above, finely granulate on the sides; 

 post-orbital ridges terminating bluntly before; cervical groove sinuate, inter- 

 rujjted on each side; no lateral spine, branchiostegian spine minute; areola 

 narrow, equal in length to about one half the distance from the cervical groove 

 to the tip of the rostrum. Abdomen punctate, pleural angles rounded off, hind 

 border of anterior section of the telson bispinose on each side. Anterior process 

 of the epistome triangular, with slightly convex sides. Antennal scale short and 

 very broad, truncate at the anterior end. Chelipeds of moderate length ; upper 

 margin of the meros serrated, below there are two series of spines; carpus tuber- 

 culate and spinulose on the inner face ; chela of moderate proportions, with slender 

 fingers; superior margin of the hand spinulose, outer and inner faces spinu- 

 loso-tuberculate ; dactylus spinulose tlirough the proximal quarter of the su- 

 perior border. Basal segment of last pair of thoracic appendages provided with 

 a crest which is produced on the inner side into a projecting tooth. Third seg- 

 ment of thu'd and fourth pairs of legs hooked. First pair of abdominal append- 

 ages rather short, tip truncate, outer part furnished with a prominent horny 

 tooth and two minor denticles, inner part terminating in a straight spine, the 

 end of which does not reach to end of the largest tooth of the outer part. 



Length 45 mm., carapace 23 mm., areola 7.5 mm., width of areola 5 mm. 

 Length of hand 17.5 mm. Length of palm 8 nmi., width of palm 5.5 mm. 

 Length of fingers 9.5 mm. 



Annulus ventralis of the female transversely broad, with a deep sigmoid 

 sulcus which is open in front. 



St. Francis River, Greenway, Clay Co., Arkansas, Aug. 1894, S. E. Meek 

 coll. M. C. Z., No. 7,336, 10 specimens, cf and 9 . 



This species is allied to Cambarus evermanni Fax. from Pensacola, Fla. 

 It differs in having the upper surface of the rostrum flatter, with depressed acu- 

 men, the areola narrower, the hand broader, and also by the different character 

 of the tips of the male appendages. It falls into the group of species represented 

 by C. evermanni Fax., C. barbatus Fax., C. wiegmanni Erichs., C. hinei Ortm., 

 and C. alleni Fax. 



