Feb. 6, 1849.] Linnean Society. 15 



Mr. Blackwall concludes his paper by proposing the name of 

 falces for the instruments by which spiders seize and destroy their 

 prey ; the term mandibles being obviously improper for organs which 

 do not, as Mr. W. S. MacLeay has plainly shown, constitute any 

 part of the oral apparatus ; and that of chelicera, proposed by M. La- 

 treille, implj^ing an hypothetical analogy to the antennae of hexapod 

 insects, from which they differ so widely both in structure and in 

 function. He adds, that he has observed the labrum in a low state 

 of development in species belonging to numerous genera, and that 

 it is attached by its base to the superior surface of the palate, but 

 that the extremity, which is free and usually round or somewhat 

 pointed, can be shghtly elevated, depressed, extended, retracted and 

 moved laterally at -nill ; and mentions that Professor Owen has de- 

 tected a rudimental labrum in spiders of the genus Mygale. To 

 apply the term mandibles to organs originating above the labrum, 

 and therefore not situated within the mouth, is evidently erroneous ; 

 and the author ventures to anticipate, upon anatomical consider- 

 ations, that future investigations will lead to the conclusion that the 

 mandibles of the Araneidea are confluent with the palate. 



January IG, 1S49. 



E. Forster, Esq., V.P., in the Chair. 



James Hepburn, Esq., and Frederick Salmon, Esq., were elected 

 Fellows. 



Read the commencement of a memoir " On the Anatomy of 

 Diphyes, and on the unity of Composition of the Diphyid<E and 

 PhysophoridcE." By William Huxley, Esq., Assistant- Surgeon of 

 H.M.S. Rattlesnake. Communicated by the President. 



February 6. 



E. Forster, Esq., V.P., in the Chair. 



Adam White, Esq., F.L.S., exhibited a numerous series of draw- 

 ings, chiefly from the monuments lately brought from Nineveh by 

 Dr. Layard, and read the first portion of a memoir on the animals 

 sculptured thereon. 



A series of specimens of the natural order Cy cades was exhibited, 

 and a portion of them presented to the Society, by James Yates, Esq., 

 F.R.S.. F.L.S. &c. 



