examination is far better, in Iiis opinion, tlian an assimilation to nor- 

 inality, founded on strained and mistaken relations, which invites in- 

 dolence to believe and slumber. 



M. GeofFroy-Saint-Hilaire concludes by repeating his request for 

 a literai copy of the \vhole of the letter addressed by Lieut. the 

 Honourable Lauderdale Maule to Dr. VVeatherhead. If the facts 

 contained in it, he remarks, should make him change his opinion, so 

 much the better : he vvould rather be put right, than indulged in 

 any vfevvs formed a priori,; in this vvay he learns more; and it is to 

 himalvvays more gratifying to get rid of an error in science than to 

 introduce into it an additional observation. 



TheVice-Secretary stated, that the request of M. Geoffroy-Saint- 

 Hilaire for a copy of the letter in cjuestion had been complied with. 

 He also referred to the Proceedings of the Committee of Science 

 and Correspondence, Part II. p. 179, for an account of the glands 

 discovered in Echidna by Mr. Ovven, who, in his observations there 

 published, briefly adducesseveral reasons \vhy little difficuity should 

 be experienced in the consideration of the Monotremata as oviparous 

 or ovoviviparous, and at the šame time as mammiferous animals. 



A letter was read from \Vilh'am Willshire, Esq.j Corr. Memb. 

 Z.S., H, M.'s Vice-Consul at Mogadore, giving an acrount of a 

 Reptile, known by the Arabs under the name of ei Dub. A living 

 specimen of the animal, presentcd to the Society by Mr. Willshire, 

 accompanicd the iettcr. lt is the Uromastyx acanthimirus, de- 

 scribed and figured by Mr. Bell in the first voiume of the ' Zoological 

 Journal,' from specimens brought from Fezzan by Capt. Lyon. The 

 Duh is noticed by Marniol, Capt. Lyon, and other travcllers; bnt 

 the precise species to which the reptile so named \vas referrible had 

 not, previously to the arrival of Mr. Willshire's specimen, been sa- 

 tisfactorily ascertained. 



A note from Col. Hallam was read, accompanying dravvings of 

 the Mango-Jish, Polynemus paradisceus, Linn.; and of tvvo indi- 

 viduals of a race of pigs with only t\vo legs, the hinder extremities 

 being entirely wanting. The latter, Col. Hallam statos, were ob- 

 served "at a town on the coast in the Tanjore country, in the year 

 1795 : they \vere from a father and mother of a similar make, and 

 the pigs bred from them were the šame." 



The exhibition was resumed of the coUection of Shells formed by 

 Mr. Cuming on the vvestern coast of South America, and aniong 

 the islands of the South Pacific Ocean. The new species brought 

 on the present evening under the notice of the Society \vere accom- 

 panicd by characters by Mr. G. B. Sovverby. 



Genus Byssoarca, Sivains. 



Byssoarca Lithodomus. Bj/ss. testu elongatd, cuneiformi, suh' 

 cylindraced, {utpliirimum erosd,) concinne dccussato-striatd ; 

 latere antico breviore, obliątie truncato, postico elongato, declivi, 

 rotundnto-aciiminato ; ared ligamenti profiindd, ligamento an- 



