440 Bibliographical Notice. 



hind win^ beneath with a large black cell-spot and a sub- 

 terminal line, parallel with termen, composed of paired vein- 

 dots, the proximal black, the distal white. 



San Antonio, W. Colombia, 5800 feet, December 1907 

 (M. G. Palmer), type and a second $ ; Torne, Colombia, 

 August 1907, one £ . I have seen other examples. 



Distinguished by the triangular shape of the central band. 

 C. peninsulata, ab. (bon. sp. ?) continens, Warr. Nov. Zool. 

 xiv. p. 286, comes nearest to it, but has more markings in 

 the distal area of fore wing, the angle in termen less 

 strong, &c. 



[To be continued.] 



BIBLIOGRAPHICAL NOTICE. 



Catalogue of the Indian Decapod Crustacea in the Collection of the 

 Indian Museum. — Part I. Brachyura. Fasciculus II. The 

 Indian Freshwater Crabs — Potamonidse. By A. Alcock, CLE., 

 M.B., LL.D., F.H.S., &c. Calcutta, 1910. 



The freshwater crabs of the family Potamonidae are of special 

 interest to the student of geographical distribution, but, like many 

 other groups of freshwater animals, they offer peculiar difficulties 

 to the systematist. In this memoir Lt.-Col. Alcock not only pro- 

 vides exact and detailed descriptions of all the forms (including 

 many new species and varieties) found within the limits of British 

 India, but also gives an entirely new aspect to the classification 

 of the family by calling attention to some important structural 

 characters, hitherto overlooked, which seem to afford a satisfactory 

 basis for the delimitation of subfamilies and genera. He discusses 

 the distribution of the Indian species, pointing out that while 

 " Blanford's zoological subdivisions of the Indian Empire, which 

 are based on the present distribution of vertebrates, suit the Pota- 

 monidae in a general way . . . that author's physical subdivisions of 

 the area have, as a rule, a much more exact correspondence with 

 the tracts in which the constituent groups of the family are con- 

 centrated." The memoir is distinguished by those qualities of 

 lucidity, insight, and breadth of view which students of the Decapod 

 Crustacea have learned to expect in the writings of the former 

 {Superintendent of the Indian Museum. 



