27 



in length to thc interior jiair ; in the Lol. gultata, Grant, tlie uppt-r 

 pair are shorter than the lower. 



Dr. Grant described in detail the new species represented by his 

 specimen, and noticed some particulars of its anatomy. The trivial 

 name oiguttata is applied to iton account of the existence on the lower 

 half of the mantle, and chiefly on its back part, of about fourteen leurge 

 round dark ppots, which are remarkablydistinguished fromthe speckled 

 apj)earance of the mantle generally. 



The paper was accompanied by a dra\ving of the animal. It will 

 be pubUshed in the Transactions of the Society. 



Mr. Yarrell read a Paper "On the Laws which regulate the Changes 

 of Plumage in Birds." 



In this paper Mr. Yarrell embodied with greater developement the 

 observations on the šame subject, \vhich he communicated to the So- 

 ciety on January 8th (seepage9). He also entered into some details 

 of the origin and growth of the feather. He referred particularly to 

 the labours of Montagu in our own country as having cleared away 

 many difficulties in tracing specific identity, that persevering omitho- 

 logist having by a long series of observations distinguished and re- 

 corded various periodical appearances. 



Age, sex, season, and disease were enumerated as the principai 

 causes of changes in plumage, and the various modes by whichthese 

 changes were efFected in the appearance of the birds were severaUy 

 alluded to. The laws by which the assumption of plumage in young 

 birds apjjears to be governed were also stated, vi^ith nimierous refer- 

 ences to partieular families of birds in which the operation of these 

 laws was most apparent. The moulting and its consequences were 

 also pointed out. 



Some of the principai facts detailed in this communication were 

 illustrated by observations and notes made on the changes in various 

 birds at the Gardens of the Society, and the changes in plumage from 

 youth to age, as well as the assumption of partieular colours at the 

 approach of the breeding season, vi^ere shown by a series of feathers 

 of difFerent birds, arranged on cards in the order in which the extent 

 of change appeared most obvious. 



Mr. Yarrell stated his belief that most of the conspicuous changes 

 observed in birds were induced by an altering or altered statė of the 

 6exual organs. 



