150 PROCEEDINGS OF THE ACADEMY OF 



Dimensions. Size of the largest specimen. Length 4 mill., breadth 115 

 mill., heigth 1 mill. Most of the specimens do not exceed two-thirds of these 

 dimensions. 



Bab. Laguna Honda, California. Rev. J. Rowell. My cabinet and cabi- 

 net of Mr. Rowell. 



Observations. This species is smaller, thinner, and wants the convex lateral 

 margins of our Anc. rivularis, Say. It agrees with that shell, however, in the 

 greater width of its anterior end, while in the shape of its lateral margins it 

 resembles Anc. parallelus, Hald. It is much the smallest of our species. 



Planorbis ammon, Gould. Pajaro River, Monterey Co. 

 Planorbis trivolvis, Say. Mountain Lake. 

 Planorbis gracilentus, Gould. Mountain Lake. 

 Planorbis vemicularis, Gould. Mountain Lake. 

 Planorbis orercularis, Gould. Mountain Lake. 

 Planorbis Newberryi, Lea. Clear Lake. 



(Communicated by the Smithsonian Institution.) 



Notes on the BIRDS of Jamaica. 

 BY W. T. MARCH. 



With remarks, 

 BY S. F. BAIRD.* 

 I. 



VULTURIDiE. 



1. Cathartes aura. The John Crow Vulture is the soaven-er oi tropica: 

 towns and villages, and so highly are his services in this respect appreciated, 

 that he is, in some of the islands, considered entitled to legislative protection. 

 An ordinance of the corporation of the city of Kingston imposed a penalty on 

 any person destroying one of them within the precincts of the city. The oc- 

 currences related by Mr. Gosse, in "Birds of Jamaica," would seem to lead 

 to the inference that the two senses of seeing and smelling, sometimes singly, 

 and at other times unitedly, give to the aura the facility with which he traces 

 his food ; but they are not conclusive. Is his sense of smelling so acute as 

 to enable the John Crow to distinguish, at a distance, the stench of a putrid 

 carcass from the atmosphere of offensive effluvia emanating from, and float- 

 ing about, his own vile body ? With the knowledge that, in the tropics, a 

 dead carcass, or dying animal, and often even fresh garbage, is quickly sur- 

 rounded and covered by swarms of flies, hovering, and buzzing above and 

 about it, or the place in which it is deposited, may we not be equally led to 

 ihe conclusion, that the Vulture is directed by the flies, aud that sight alone 

 is the sense by which he finds his necessary food ? By whatever sense he is 

 led, he certainly traces his food from a far distance. When a dead carcass 

 has been discovered by some, numbers of other Vultures are directed by the 

 motion of those gathering together, and soaring at a great height, sweeping 

 round and round in irregular circles. Shortly after the commencement of 

 the Rebellion of 1831, and long after its suppression, the Aura Vulture was a 

 rare object in the landscape of the midland and eastern parishes ; they had 

 all departed for the scene of carnage in the West, where they remained for 

 many months. 



The Cathartes aura breeds in solitary pairs. I have never seen them, or 



^Specimens ot most of the birds, and of the eggs described, have been presented by Mr. Maich 

 to the Smithsonian Institution, under the numbers which they bear in big communication. (E 



[May, 



