Zoological Society. 123 



considerably larger than those of Man ; its average size in vulgar 

 fractions of an English inch is 1-2865. 



M. Mandl* discovered that the blood-corpuscles of the Elephant 

 are the largest at present known belonging to the Mammalia, and I 

 subsequently found that those of the Capybara vi^ere, as far as we 

 then knew, next in size, as noticed in my Appendix to Gerber's 

 Anatomy, pages 5, 8, and 50. 



But it now appears that the blood-corpuscles of the Sloth are 

 larger than those of the Capybara, and, among mammiferous animals, 

 second only in magnitude to the corpuscles of the Elephant. 



For the sake of comparison, some of my measurements of the 

 average size of the largest blood-discs of Mammalia are here set 

 down in the order of the magnitude of the discs, and in vulgar frac- 

 tions of an English inch. 



Elephas Indians, Cuv 1-2745 



Bradypus didactylus, Linn 1-2865 



Balcena Boops, Auct 1-3099 



Hydroch(£rus Capybara, Erxl 1-3216 



Phoca vitulina, Linn 1-3281 



Dasypus villosus, Desm 1-3315 



Myopotamus Coypus, Desm 1-3355 



Pithecus Satyrus, Geoff. 1-3383 



Dasypus sex-cinctus, Auct 1-3457 



Numerous other measurements are appended to the English ver- 

 sion of Gerber's Anatomy. 



It has been said that the blood-corpuscles are larger in omnivorous 

 than in herbivorous and carnivorous animals. To the facts which I 

 have elsewhere t shown to be at variance with this opinion, it may be 

 added that the oviparous Vertebrata, whatever may be the nature of 

 their food, have larger blood-corpuscles than Mammalia, and that 

 the size of the blood-corpuscles of many carnivorous birds exceeds 

 that of the corpuscles of several of the omnivorous species. 



Finally, the Two-toed Sloth, which is a purely vegetable feeder, 

 has, excepting the Elephant, the largest blood-corpuscles hitherto 

 observed in any mammiferous animal. 



** Mr. Hinds' resumed description of new Shells, from the cabinets 

 of Sir E. Belcher and H. Cuming, Esq." 



RiNGicuLA, Deshayes. 



RiNGicuLA GRANDiNOSA. RiTi. testd ovtttd, vetusd, IcBvigatd, politd ; 



anfractibus rotundatis, ultimo magna, subquadrato, rotundato ; 



columelld superne valde callosd, denticulatd. Axis 1| lin. 



Hab. Bais, island of Negros ; in six fathoms, coarse sand : Caga- 



yan, island of Mindanao ; in twenty-five fathoms, sandy mud : Cat- 



* Anatomic Microscopique, Paris 1838, Prem. Liv. p. 17. M. Mandl's 

 observation refers to the blood-corpuscles of the African elephant; it was 

 those of the Asiatic species that I examined. 



•f Appendix to Gerber's Anatomy, p. 4-5, 



K2 



