600 Zoological Proceedings of Socielies. 



prives the animal of motion, Mr. Main is inclined to consider the 

 first surmise the more probable. 



An extract was read from a Letter from Dr. Rigby to Mr. R. 

 Taylor, dated Berlin, on the ova of the Hirudo medicinalis. It 

 was accompanied by some specimens. 



An Account of Margarodes, a new genus of Insects found in 

 the neighbourhood of Ants'' Nests ; by the Rev. Lansdown 

 Guilding, B.A., F.L.S., &c. was also read. Mr. Guilding, (after 

 quoting Dr. Nugent (Geol. Trans, vol. v. p. 463), who states 

 that the ground pearl, improperly supposed to be fossil, is found 

 in prodigious quantities in the furrows of the land in Antigua 

 when newly turned up, and suggests that it may be the produc- 

 tion of an insect,) informs us that he has succeeded, by watching 

 some that he preserved in moist marl, in detecting the insect 

 which issued from them. He conceives it to be a parasite on the 

 ants, whose formidable numbers in the dry islands they are 

 calculated to keep down. The entire want of a mouth is re- 

 markable in this new insect, the food being absorbed by tubes 

 in the fore-claws. It also possesses the extraordinary power of 

 throwing out long filaments, when in dry situations, supposed to 

 be for preserving itself by obtaining moisture. Its scales efF r- 

 vesce and disappear in nitric and muriatic acid ; sulphuric acid 

 turns them black ; and vinegar slowly decomposes them. In 

 flame they burn like horn. Mr. G. is uncertain at present what 

 station is to be assigned to this insect. 



Dec. 18. — Three new species of Land Tortoises were exhi- 

 bited by Mr. Bell ; Testudo pardaUs, Test, actinodes, and Test, 

 tentoria J described by that gentleman in the last number of our 

 Journal. 



Jan. 15, 1828. — Some specimens of Janthince were exhibited 

 by L. W. Dillwyn, Esq., washed ashore in July last in Oxwick 

 Bay, near Swansea, many of them picked up alive, and yielding 

 a beautiful dye. Specimens of the Medusa Velella and Med. 

 Navicular were found with them. 



