392 CRAYFISHES. 
narrower than in the typical C. bartonii; the areola is so narrow as to allow barely 
room for two closely approximated longitudinal rows of dots; the rostrum is a 
little longer than in C. bartonit, with more convergent margins and a longer 
acumen; the upper or superior border of the hand and movable finger are more 
distinetly tuberculate; the fingers are shorter, stronger, and more heavily ribbed, 
and the outer border of the immobile one is more heavily and coarsely punctate. 
The posterior internal spine of the carpus is obsolete; the anterior process of the 
epistoma is more broadly triangular. 
Type specimen, M. C. Z., No. 3,812, W. 8S. Blatchley, Bloomington, Ind. 
%, form II. Measurements:— Length, 67 mm., length of carapace, 33 mm., 
length of areola, 14 mm., breadth of areola at middle, 1 mm., length of right 
chela, 24 mm., length of right dactylus, 16 mm. 
Other localities:— Fall Creek, Indianapolis, Ind. (M. C. Z., No. 3,796), New 
Albany, Ind. (M. C. Z., No. 3,618), Irvington, Ind. (U. 8. N. M., Nos. 19,738, 
22,204), May’s Cave, Monroe Co., Ind. (U.S. N. M., No. 19,740). 
The peculiarities of this crayfish, which appears to be a common form in the 
State of Indiana, were first pointed out in my Notes on North American Cray- 
fishes, Proc. U. 8S. Nat. Mus., 1890, 12, p. 622. It has been described and 
figured, as C. bartonw, by Mr. W. P. Hay in the Twentieth Ann. Rep. of the 
Department of Geology and Natural Resources of Indiana, 1896, p. 437-489. 
The features which distinguish it from the typical form of C. barton are so pro- 
nounced as to render it necessary to mark it as a subspecies of C. bartonii if not 
as a valid species. In the great relative length of the posterior section ‘of the 
carapace it resembles C. bartoni tenebrosus Hay from the Mammoth Cave of 
Kentucky. 
According to letters which I received from Dr. John Sloan of New Albany, 
Ind., in the year 1883, this crayfish was always found by him in that region to be 
a denizen of standing ponds and still water, being replaced by C. sloanii in the 
running streams. On the contrary, both Mr. W. P. Hay (l. ¢., p. 489) and Mr. 
A. M. Banta (The Fauna of Mayfield’s Cave, Carnegie Inst. of Washington, 
Publ. No. 67, Sept. 1907, p. 73-75) aver that it is most commonly found in springs 
and small streams of clear running water where it seeks concealment under stones 
or in shallow burrows. 
Messrs. Hay and Banta have found this form a frequent inhabitant of the 
caves of southern Indiana in company with the blind species, C. pellucidus. 
Those that dwell in the caves appear to attain a greater size than those in the 
surface waters, specimens in the Mitchell Caves, Lawrence Co., often exceeding 
