112 PROCEEDINGS OF THE ACADEMY OF [Jan., 



collected by William Wagner, Thomas H. Montgomery, Jr., and 

 himself. 



CALLIANASSA Leach. 



The glaucouitic sands of the New Jersey Cretaceous are ill- 

 adapted for the preservation of delicate structures, and therefore 

 only the hard large claws of these soft-bodied Macrura are found. 

 Most of the species descril)ed from the Cretaceous, Eocene and 

 Miocene of Europe are likewise based upon chelre. 



In the United States one Eocene species has been described, C. 

 ulrichi White, ^ from specimens collected by Mr. E. 0. Ulrich near 

 Little Rock, Ark., in a bed at first supposed to be Cretaceous. The 

 specimens before me were collected by Mr. C. W. Johnson at 

 Mabelvale, Ark. The propodite in this species is short and squar- 

 ish, much as in C. conradi ; the lower border is somewhat crenate, 

 and well-preserved specimens show a tuberculate tract on each side 

 behind the commissure between the fingers. The hand is com- 

 pressed, as in C. conradi. 



In Europe the fossil species from Mesozoic and Tertiary strata 

 are numerous and an excellent account of them has been given by 

 Milne-Edwards,* while notices and descriptions of various species 

 occur in the works of many other authors. The older species are 

 very similar to living forms, weak and soft-bodied burrowers in 

 the sand, and yet the genus has outlived most of its companions 

 on the shores of the Cretaceous seas. There is nothing like being 

 adapted to your circumstances. 



Our species apparently belong to that division of the genus in 

 which the fingers are of equal length, but they are clearly distinct 

 from any described European form. 



Callianassa mortoni n. sp. PI. I, figs. 1-7. 



Propodite (figs. 1-4) rhombic, its breadth about two-thirds the 

 length, the outer face (fig. 1) very convex, the greatest convexity 

 posterior and nearer the upper side. Surface nearly smooth, usually 

 showing a series of four distant punctures extending backward 

 from the root of the fixed finger, and two on the other or more 



' C. A. White, Proc. U. S. Nat. Mas., Ill, 1830, p. 161 ; IV, 1831, p. 

 137, PI. 1, figs. 10, 11 (left propodite); G. H. Harris, Ann. Rep. Qeol. 

 Surv. Arkansas, II, 1892, p. 30, PI. 1, fig. 2a, 2b (left hand). 



* Anriales des Sciences NaturelUs, 4 sen, XIV, ZojL, p. 301 (1860); a 

 supplement in Nouv. Arch, du Mas., 1870, Vol. VI. 



