Rostrum without lateral teel 



48 A REVISION OF THE ASTACID.E. 



C. Carolinus, and C. gracilis resemble C. Diogenes of Group III. in the general 

 form of body, linear areola, small antennal scale, broad chela, etc. The fore 

 border of the carapace is angulated behind the antenna? in C. simulans, 

 C. Mexicanus, C. Cubensis, and C. gracilis ; not angulated in C. adeem and 

 C. Carolinus. The rostrum is armed with small lateral teeth in C. Cubensis; 

 in the other species of this group the rostrum has no lateral teeth. 



Of the species belonging to this group, Hagen knew only C. advena and 

 C. Carolinus. These were placed by him, as aberrant forms, in Group III. 

 ( C. Bartonii). 



Rostrum with small lateral teeth, areola broad. C. Cubensis. 



/Areola of moderate width. Chela subcyliiidrical. C. Mexicanus. 

 \ Areola narrow. Antenna! scale large and broad. C. simulans. 



■ Front margin of carapace angulated 



behind antenna 1 . G. gracilis. 



* Areola linear, or obliterated in the middle. \ 



Front, margin of carapace not angu- 

 lated. C. advena, C. Carolinus. 



16. Cambams simulans. 



Plate I, tig. 3, Plate VIII, tigs. 3, 3', 3 a, 3 a'. 



Cambarus simulans, FaxoNj Proc. Amer. Acad. Arts and Sci., XX. 112, 1SS4. 



Male, form I. — Rostrum broad, deeply excavated ; margins raised into 

 sharp crests, which overhang the base of the sides of the rostrum, converging, 

 sinuated before the tip to form the short acumen ; no lateral spines ; the 

 acumen is barely margined. Post-orbital ridges subacute in front, divergent 

 and ending in slight callosities behind. Carapace ovate, narrowing in front, 

 gastric area smooth, cardiac area lightly punctate, sides granulate; anterior 

 border notched behind the antenna) ; cervical groove sinuate, split on the 

 sides, with a minute terminal branchiostegian spine; no lateral spine; areola 

 more than one half as long as the distance from the point of the rostrum to 

 cervical groove, narrow, carinate, expanding into an anterior and a posterior 

 triangular field ; two longitudinal dotted lines run along the areola from the 

 anterior triangle to the posterior triangle, which is irregularly and sparsely 

 dotted. Abdomen broad, shorter than carapace, punctate, posterior margins 

 of pleura obliquely convex; hind margin of anterior segment of telson bi- to 

 multi-denticulate on each side, posterior segment short, hind border almost 

 straight; median rib of inner plate of swimmeret ends inside of the mar- 

 gin. Basal segment of antennule with a spine below. Antennae shorter than 



