98 SIXTH REPORT 1836. 



On the Foot of the ' Two-toed' Ostrich (Struthio Camelus), By Henry 

 Riley, M.D. 

 In this communication Dr. Riley showed that the number of toes in 

 the foot of this bird was the same as that of the Cassowaries and the 

 Nandua or Struthio Rhea. The difference observable is, that in Stru- 

 thio Rhea the internal toe is fully developed, while in the ' two-toed ' 

 ostrich it is in a rudimentary state, and completely covered and con- 

 cealed by the integuments of the foot. In the specimen exhibited (a 

 young bird) there was a well defined condyle on the inner side of the 

 phalangic extremity of the tarsal bone, smaller but similar in all other 

 respects to the other two heads or condyles, serving the purpose of re- 

 ceiving the first phalanges of the two toes already described by natu- 

 ralists. Articulated with this condyle was a rudimentary toe about an 

 inch and a half in length, and consisting of two phalanges; the first or 

 tarsal phalange completely ossified, one inch long, cylindrical, and of 

 the calibre of a crow's quill. It was articulated with a second pha- 

 lange, not yet ossified, cartilaginous, and barely half the length of the 

 preceding. 



On the Manati or Cowfish of the Inland Waters of Guiana. By John 

 Hancock, M.D. 



ITiis communication contained the author's observations on the na- 

 tural history of the Manati, descriptions of the principal points of its 

 remarkable organization, and habits of life. 



Mr. Curtis exhibited some specimens of the terminal shoots of a 

 Pinus which had been attacked by the Hylurgus piniperda, and made 

 some remarks upon the habits of this insect. 



Robert Ball, Esq. of Dubhn, exhibited for the purpose of eliciting 

 information, several crania of a large species or rather genus of Seal, 

 which had hitherto unaccountably escaped the notice of naturalists as a 

 native animal, though very common on the coast of Ireland. 



Professor Nilsson of Lund pronounced the crania'^to belong to the 

 Halichcerus griseus (synonymous with Phoca Gryphus of Fabricius), 

 found in the Baltic, North Sea, and Iceland, and recorded as the type 

 of a new genus in his Fauna Suecica. 



Mr. Ball also exhibited the skull of a seal taken on the coast of Sligo, 

 agreeing with the principal descriptions of Phoca Vitulina, and much 

 less common than the foregoing on the shores of Ireland ; and Doctor 

 Riley produced the skeleton of a seal captured in the Severn, very di- 

 stinct from the preceding (though under the same denomination). Pro- 

 fessor Nilsson stated the former to be Phoca variegata, and the latter 

 Phoca annellata, which with P. barbata had long been confounded 

 under the name of P. Vitulina. 



On Aranea avicularia. By S. Rootsey, M.D. 



