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. bartonii, with more convergent margins and a longer 

 acumen; the upper or superior border of the hand and movable finger are more 

 distinctly 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 The posterior internal spine of the carpus is obsolete ; the anterior process of the 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 l^roadly triangular. 



Type specimen, M. C. Z., No. 3,812, W. S. Blatchley, Bloomington, Ind. 

 cf, 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 locahties:— 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 ci-ayfish, 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. S. Nat. Mus., 1890, 12, p. 622. It has been described and 

 figured, as C. bartonii, 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. bartonii 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. bartonii 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. c, 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 si5e than those in the 

 surface waters, specimens in the Mitchell Caves, Lawrence Co., often exceeding 



