228 Zoological Society. 



having the lores, base of lower mandible, lower portion of the ear- 

 coverts, and the chin and throat, the same bright yellow as the rest of 

 the under parts ; the feathers of the crown are pale shafted, which 

 is not the case in poliogenys ; the tail is [)ale dusky, the two outer 

 feathers only being white on the apical portion of the inner web, the 

 basal portion of which is dusky ; the outer web in both is pale dusky 

 green ; the other ten are fringed with greenish on the outer web. The 

 wing in affinis is a quarter of an inch longer, but has the same mark- 

 ings ; the tarsus is also longer by a tenth of an inch. Other charac- 

 ters agree in both species. The bill in this and poliogenys is broader 

 than in A. xanthoschistos^ Hodgson. 



Hab. Nepal. (No. 920*. Hodgs. Catal.) 



. Abrornis albogularis, Hodgsott. . r r . . r 



jf. Forehead, lores, over and under the eyes to nape, and ear-coverts 

 bnghtish ferruginous, the crown being dusky ferruginous, passing 

 to yellowish olive-green on the back and shoulders; the rump 

 yellowish ; wings black, margined with the colour of the back ; tail 

 pale dusky greenish, edged exteriorly throughout with yellowish- 

 green ; throat and base of lower mandible white, the feathers black 

 at base ; breast bright yellow ; abdomen white, vent yellowish ; bill 

 horny, paler beneath ; feet pale horny ; the rictorial bristles black, 

 strong, nearly as long as the bill. 



Length, 3^ inches; of wing. If; the first quill ^ an inch shorter 

 than the second ; third yo^hs longer than the first ; fourth, fifth and 

 sixth nearly equal, the fifth being the longest ; tail, \\ inch ; bill to 

 frontal plumes, ^V J to gape, y^; tarsus, y^^; middle toe and claw, ^^ ; 

 hind ditto, -| ; tarsus and hind claw strong. 



Hab. Nepal. (No. 936. Hodgson's Catal.) 



On the Genus Modiolarca. 

 By Dr. John Edward Gray, F.R.S., P.B.S., V.P^Z.S. etc. 



In the Synopsis of the British Museum for 1840, pp. 144, 155, 

 I established a family of bivalve shells under the name of Crenellidce, 

 for the genera Crenella and Modiolarca, taking the character of the 

 family from the animal of Modiola trapezina, the type of the genus 

 Modiolarca, the only one that had then come under my examination. 

 The following were the characters given : — 



" The family of Crenellidce chiefly differs from the former {Myti- 

 lid(B) in the mantle lobes being united together so as to leave only 

 two posterior holes for the entrance and exit of the water, and a slit 

 for the foot and beard. The hinge-margin is denticulated at each 

 end, and the umbo is nearly central." 



Shortly after, Mr. Alder described the animal of the British Cre- 

 nella undulata, and found that the mantle was nearly as much open 

 as that of the Modiolce, and complained of the inaccuracy of the 

 description ; the fact being, that the two genera had very different 

 animals, and that Crenella had been wrongly referred to the group, 

 and taken as the patronymic of it. 



