Prof. Eschricht on the Gangetic Dolphin. 279 



simplici (nee crenata), striis minutissime subcrenatis v. subcris- 

 pulis; anfractu ultimo basi sulcato obtuse bicristato; apertura 

 oblique ovato-pyriformis subrhomboidea, lamella supera tenui 

 distincta, infera crassiore magis immersa antice dilatato-obsoleta, 

 lunella nulla v. inconspicua ; plicis palatalibus duabus tuberculi- 

 formibus, supera (subcolumellari) inconspicua subimmersa, in- 

 fera distinctiore subprominula alba; peristomate continuo soluto 

 expanso albo-limbato. 



Long. 13-14, lat. 2±, long, apert. 2f-2| mill. 



Hab. prope Lisbon, L. J. Moniz. 



Differt a C. rugosa (Drap.), Pf. Mon. ii. 475, testa graciliore 

 angustiore apice distincte mamillata, lunella nulla v. inconspicua, 

 &c. An "C. rugosa,Move\et, Moll. duPort. p. 75," Pf. I.e. eadem? 



Cyclostoma, Lam. 

 §. Hygrobium, Lowe. 



70. Cyclostoma Lyonnetianum. — Differt a C. lucido, Lowe, 

 testa multo minore elevato-trochoidea exilissime spiraliter striata, 

 anfractu ultimo carinato-angulato. Gibbum Lyonnetianum, Pall., 

 forma quodammodo refert. 



Hab. in Madera. Inv. Wollaston. 



Madera, Dec. 1851. 



XXIV. — On the Gangetic Dolphin. By Dan. Fred. Eschricht, 

 Professor at the University of Copenhagen. Being a Supple- 

 ment to his Memoirs on Whales. Transactions of the Royal 

 Danish Academy of Sciences, 5th Series, vol. ii. (separately 

 printed, Copenhagen, 1851, 4to.) Translated from the Danish 

 by Dr. Wallich, F.R.S., Vice-Pres. Linn. Soc. 



[Concluded from p. 188.] 



Zoologists have agreed, since the time of Cuvier, that the 

 proper place of a vertebrate animal in the system is perhaps 

 most safely decided by the structure of its skeleton ; and if this 

 rule holds good as to the class generally, it probably applies still 

 more forcibly to Cetacea than to any order, because here, under 

 the determinate outer form of a fish, we have concealed the perfect 

 structure of a mammal, in which another further difference mani- 

 fests itself, which has hitherto been rated on too low a scale. Of 

 the correctness of this assertion, the skeleton of the Gangetic dol- 

 phin affords the best proof. Lebeck and Roxburgh had already 

 shown the striking discrepancies in the form of its beak, its 

 .breast-fins and spiracle ; but it was only after Cuvier had described 



