108 A REVISION OF THE ASTACIDJE. 



Female. Hand small, fingers not gaping, ciliated within ; sternum 

 between fourth pair of legs plane ; an mil us ventralis bilaterally symmetrical, 

 anterior border bituberculate, posterior border unituberculate, transverse 

 fossa deep, recurved at each end. 



Measurements of male, form I. Length of body, 49 mm. Length of 

 carapace, 25 mm. Length of rostrum, 6 mm. Length from end of rostrum 

 to cervical groove, 15.5 mm. Length from cervical groove to hind border 

 of carapace, 9.5 mm. Width of areola, 2 mm. Length of abdomen, 25 nun. 

 Length of chela, .23.5 mm. Length of internal margin of hand, 9.5 mm. 

 Breadth of chela, 11.5 mm. Length of movable finger, 14 mm. 



Two specimens, first form of male and female, in the Museum of Compar- 

 ative Zoology, from Irondale, Mo. 



This species has the general form of body, rostrum, and chelee of the 

 C. Bartonii group, together with the male abdominal appendages of the 

 C. affiins group. These appendages have a projecting shoulder at the base 

 of the rami, on the anterior edge, as in C. rubious, C. Pu/iMiiii, etc. C. iiii- 

 munis and C. Mississippiensis, belonging to the C. affinis group, also have the 

 rostrum devoid of lateral spines, but in general habit of body they do not 

 resemble C. Bartonii and its allies, as is the case with the present species. 



47. Cambarus rusticus. 



Plate IX. flgs. 8, 8', 8 a, 8 a' (flrst abdominal appendages of male). 



Cambarus rusticus, GIRARD, Proc. Acad. Nat. Sci. Pliila., VI. S8, 1852. 



Cambarus rusticus, HAGEN, 111. Cat, Mus. Comp. Zool., No. III. p. 71, PI. I. figs. 80-83, PI. III. fig. 161, 



18/0. 



Cambarus placidus, HAGEN, op. cit., p. 65, PI. I. figs. 76-79, PI. III. fig. 158, 1870. 

 Cambarus juvenilis, HAGEN, op. cit. p. 66, PI. I. figs. 29-33, PI. III. fig. 157, 1870. 

 Cambarus ntx/icus, SMITH, Rep. U. S. Coinni. Fish and Fisheries for 1872 and 1873, p. 639, 1874. (After 



II.-ILTU. No description.) 



Cambarus placidus, SMITH, op. cit.. p. 638, 1874. (After Hagen. No description.) 

 {'.,iinlii<fiix juri-iiiln, SMITH, op. cit., p. 38, 1874. (Alter Hageu. No description.) 

 Cambarus //'/'..rw/.v/,,,'//*/.?, l!rxv>Y, Bull 111. Mus. Nat Hist., No. I. p. 4, 1876. Trans. Wis. Acad. Sci., V. 



181, 1882. Geol Wis.. Surv. 1S73-1879, I. 402, ISsij. 



Camlttmis /,1,1,-iilns, FORHKS, Hull. 111. Mus. Nat. Hist., No. I. pp. 4, 19, 1876. (After Hageu.) 

 Cambarui Wiscominensis, FOUISKS, op. nit., p. in. (Al'in- r.umh.) 

 Cambarus rustifus, liiixnv. Trims. Wis. Acad. Sci., V. 181, ivs^. Grol. Wis., Surv. 1873-1879,1.402, 



1883. (Not dosrrilx',1 ) 



Cambarus /,lni-i,lHs, ]',r\i.v. Trans. Wis. Acad. Sci., V. 181, 1882. (Not described.) 

 Cambarus rnsliciis, FAXON, Proc. Amor. Acad. Arts and Sci., XX. 148, 1884. 



Male, form I. Rostrum long, narrow, concave on the sides, excavated, 

 margins thickened, dotted-lined. divergent at the base; acumen of moderate 



