112 



single clorsal fin, I)as appeaied to the šame naturalist to require 

 generic distinction, and he has accordingly described it as the type 

 of a ne\v genus, to vvhich he has given the name of Platy&ome: it is 

 evidently, from the brief notice contained in the ' Analyse,' the 

 DuIes cnudavittatus, Cuv. and Vai., or a nearly alhed species, a fish 

 which certainly ditters considerably, by its compiessed form and 

 other particulars, from many of those \vith which it was generically 

 associated by the authors lašt quoted. M.J.Liėnard has exhibiled a 

 drawing of an Acaiithurus : and M. J. Desjardins has described three 

 fishes of the genera Serranus, Labriis, and Xirkhthįjs ; and has 

 also exhibited and described specimens, obtained from the north- 

 western coast of Sumatra, of eight other fishes. 



Among the Crustacea, two species of Crabs cornnion on the coasts 

 ofthe Mauritius, and belonging to the genera Puiiunus and Pod- 

 ophthulmus, have been described and drawn by M. J. Liėnard. 



Finally, M. E. Lienard has described minutely a marine sub- 

 stance vvhich he has regarded as an Alcyonium : he proposes to con- 

 tinue to figure and describe the numerous zoophytes vvhich abound 

 in the adjoining seas to such an extent as to render the Mauritius 

 highly favourable for the pursuit of zoological studies in this beau- 

 tiful but intricate department oF nature. 



Mr. Gray exhibited living SĮiecimcns of the common Lizard, La- 

 certa agilis, Linn., for the purpose of pointing out the niarks of dis- 

 tinction betvveen the sexes. The malė is generally larger than the 

 female, and more tlistinctly coloured : the under side of hisbody and 

 base of his tail are very bright orange, vvhiie in the female these parts 

 are pale yellovvish green ; his ante-anal scale is short and transverse, 

 that ofthe female being niuch longer and hexagonal ; and the under 

 side of the base of his tail is flat, vvith a slight longitudinal niiddle 

 depression just behind the vent, this part of the tail being in the fe- 

 male rounded and convex. In April and Muy the malė may also be 

 knovvu by the base ofthe tail being dilated on the sides, just behind 

 the thigh, a dilatation probably caused by the size of the penės, vvhich 

 are retracted into these parts. 



Mr. Gray further explained various particulars of the habits of this 

 species, observed by him in individuals vvhich he had kept in a living 

 State ; and added, that in the only instancc in vvhich he had observed 

 the coitits, one alone ofthe penės was inserted. 



