113 



but differs from that species in being of a larger size, in the lighter 

 hue of the centre of the abdomen, in the striae down the centres of 

 the abdominal feathers being less strongly defined, and in the under 

 tail-coverts being buff instead of rufous. 



3. SiTTA LEXjcoPSis, Gould. 



Sp. C/t.— Crown of the head and back of neck jet-black ; all the 

 upper surface deep blue-grey ; primaries black, edged with grey ; 

 centre tail-feathers blue-grey ; lateral feathers black, tipped with blue- 

 grey ; the two outer ones on each side with a small spot of white on 

 the inner web near the tip ; face, chin, throat, breast, and centre of 

 the abdomen white, the latter slightly washed with buff; flanks and 

 under tail-coverts bright chestnut ; bill black, with a blue-grey base ; 

 legs grey. 



Total length, 5 inches ; bill, | ; wing, 3^ ; tail, 2 ; tarsi, |. 



Hab. The Himalaya Mountains. 



Remark. — This is doubtless the species described by Mr. Blyth in 

 his observations on the Sitting as nearly allied to the S. ceesia, 

 without however assigning to it a specific name, an omission which I 

 have now ventured to supply. 



4. On the species of Anomiad^. By J. E. Gray, Esa., F.R.S. 



ETC. ETC. 



The European species of Anomiad<e have been much multiplied, 

 while on the other hand the exotic species have been almost entirely 

 neglected. 



The form, substance, surface and colour of the shell, which have 

 been used to distinguish the species, were suspected by Montague to 

 be dependent on the age of the specimens and the locality in which 

 they happened to be found, and further researches have proved the 

 accuracy of these observations. 



There being in the British Museum considerable series of speci- 

 mens of this family from different localities, I have attentively exa- 

 mined them, and believe that I have observed some characters by which 

 they may be distinguished from each other, which are but little, if 

 at all, modified by external circumstances or age. 



Mr. Cuming has kindly allowed me to examine the original spe- 

 cimens of Placunanomia, described by Mr. Broderip, with some ad- 

 ditional specimens which he has since received, and thus enabled 

 me to identify the exotic species which have been described by that 

 naturalist ; and also the collection of Anomice contained in his cabi- 

 net, which has furnished me with several additional species. 



The species may be divided into two very distinct genera : — 



1. Anomia. Upper valve with three subcentral muscular scars; 

 the anterior upper lobe of the notch separated from the cardinal edge ; 

 the plug entirely shelly, and quite free from the edge of the notch. 



2. Placunanomia. Upper valve with two subcentral muscular 

 scars ; the anterior upper lobe of the notch agglutinated to the car- 

 dinal edge ; plug shelly at the top and near the body to which it is 

 attached, and with horny longitudinal laminae below and internally. 



No. CXCVII. — Proceedings of the Zoological Society. 



