Zoological Societi/. 5 1 1 



" The Yapock has very large cheek-pouches which extend far 

 back into the mouth, and of which tl\c opening is very apparent. 

 This circumstance, hitherto vmobserA'ed by zoologists, throws con- 

 siderable light upon the habits of this rare animal, which thus ap- 

 pears, like the Ornithorhynchus, to feed upon freshwater Crustacea, 

 and the larva of insects, spawn of fishes, &c. which it probably stows 

 away in its capacious cheek-pouches. For 2 inches at the root the 

 tail is covered with the same description of fine close fur as the body ; 

 from this part it tapers gradually to the point and is covered with 

 small scales, arranged in regular spiral rows, and interspersed with 

 bristly hairs, particularly on the under surface, a fact perfectly con- 

 clusive against the generally received opinion of this organ being 

 prehensile in the Chironectes. Indeed, the tail so perfectly resem- 

 bles that of the Hydromys chrysocjaster, even to the white tip, that 

 it would be impossible to distinguish these organs if separated from 

 the respective animals. The useless appendage of a prehensile tail 

 to an aquatic animal, must consequently be henceforth discarded 

 from the history of the Chironectes, and the animal allowed to take 

 its place among conterminous genera, not as a compound of anoma- 

 lous and contradictory characters, but as a regular component link 

 in the scale of existence. That its habits are purely aquatic, and 

 that it has not the power of ascending trees, is further proved by 

 the structure of the extremities. The hind feet are broad like those 

 of the Beaver ; the toes, including the thumb, united by a membrane, 

 and, with the exception of the thumb, provided with small falcular 

 claws ; the thumb, as in all the other Didelphidous Pedimana, is 

 without a claw. The fore-fingers are separate, very long and slen- 

 der, (the middle and ring-fingers the longest of all,) and the last 

 joint expanded and flattened as in the Geckos. The thumb is 

 placed rather behind the general line of the other fingers, and seems 

 at first sight to be opposable : it perfectly resembles those of the 

 American Monkeys*. The claws are very small and weak; they do 

 not extend bej'^ond the points of the fingers, nor even so far, and 

 are absolutely useless either for climbing or burrowing. Consider- 

 ably behind the others, on the outside of the wrist, there is a 

 lengthened tubercle resembling a sixth finger, but much shorter 

 than the others and without any bone. What pur^jose this unique 

 organ may serve in the economy of the animal's life, it is impossible 

 to conjecture, but the long slender fingers are probably used to pick 

 out the food which it carries in the cheek-pouches." — W. O. 



June 14. — Specimenswereexhibited of various Birds fromNorthern 

 Africa, which had recently been presented to the Society by Sir 

 Thomas Keade, Corr. Memb. Z.S. They included the Anas mar- 

 morata, Temm., on which Mr. Gould remarked that in the form of 

 the bill it approached nearly to the Pin- tailed Duck, Anas acuta, 

 Linn., although it is altogether destitute of the elongation of the 

 middle tail-feathers which occurs in that bird ; the crested Duck ; tiic 

 Gadwull; the Gurcjuney ; the /i«^, and the black-tailed Godwit, in 



* See Mr. Ogilby's remarks on the supposed antagonism of the thumb in 

 tlic American Monkeys, present volume, p. 322. 



