NATURAL HISTORY SOCIETY OF GLASGOW. 223 



1831, we do not find any farther notice of this insect; in that year 

 Swainson published, in his " Zoological Illustrations," copies of 

 both Drury's and Cramer's figures, stating that he had never seen 

 the insect. In 1837, James Duncan, in his "Natural History of 

 Foreign Butterflies," copies the same figures as Swainson, and 

 quotes his remarks in extenso ; although in 1833, i.e., four years 

 previously, Dr Boisduval published his natural history of the 

 insect, with beautiful figures. He states that it inhabits Mada- 

 gascar, and that a single specimen had been taken in Bourbon, 

 whither a caterpillar had probably been transmitted accidentally. 

 The larva feeds on the Mangifera indica. With respect to the 

 geographical distribution of this genus, a problem arises for 

 evolutionists to solve. We have two species located in the West 

 Indies, and one in Madagascar; the shortest distance between 

 these countries is across Africa and the Atlantic, but in Africa no 

 closely allied species is found, and we may therefore conclude that 

 extinct allied species connecting the two forms existed rather across 

 the Pacific than over Africa and the Atlantic. 



Professor Young, F.G.S., who was prevented from attending the 

 meeting, sent for exhibition, through Mr John Young, F.G.S., 

 specimens of a Silurian fossil, from the Girvan district. Regarding 

 this organism, Dr Young stated that his attention was called to it 

 by Mrs Pobert Gray, and for some time he thought it represented 

 some phyllopod crustacean. It belongs to a genus created some 

 years ago by the late Mr Salter, who named it Stenotheca, believing 

 that it belonged to the pteropods. Whatever the determination 

 may be worth, it is interesting to find this same form in the 

 Silurians of Scotland and North Wales ; but its pteropod character 

 is doubtful, for this reason, among others, that the valves are 

 found in pairs, and in many cases the similar margins are turned 

 towards each other, just as happens with Dictyocaris, Estheria and 

 other bivalve forms. Dr Young said he was not in a position to 

 aflftrm its crustacean character as more than a probability ; and that 

 we must therefore, meanwhile, accept the genus already established, 

 and chronicle it Stenotheca (Salter). 



Mr John Young, F.G.S., exhibitedspecimensof a small Carbonifer- 

 ous tubicolor annelid, which he discovered in the marine limestone 

 shales of the Lanarkshire coal-fields, and which he had described 

 in the London Geological Magazine for this year, under the name 

 of Ortonia carbonaria. The genus Orfonia, he stated, had been 



