100 Linnean Society. [April 20, 



Read the conclusion of Mr. Bracy Clark's "Appendix or Supple- 

 ment to a Treatise on the (Estri and CuterebrcB of various Animals." 



The first memoir to which this paper is intended as an Appendix 

 appeared in the third volume of the Linnean Transactions, published 

 in 1796. This memoir was republished by the author with consi- 

 derable additions in 1815, and a Supplement was added in the fol- 

 lowing year. Since that period much has been published on the sub- 

 ject, and Mr. Clark is desirous in consequence of making some ad- 

 ditions and corrections to his former publications. 



After adding to and modifying some of the passages contained in 

 them, he examines the validity of several species of the genus (Estrus 

 proposed by writers. He suspects (E. Trompe of Modeer and (E. 

 ericetorum of Leach to be severally the males of (E. Tarandi and (E. 

 Bovis. He believes (E. Pecorum of Fabricius to be only a dark- 

 coloured variety of (E. nasalis, L. {(E. veterinus, B. CI.) ; and is sa- 

 tisfied by an examination of the original specimen, that Dr. Leach's 

 (E. Clarkii is nothing more than a very light- coloured variety of the 

 same species. He also regards (E. lineatus of Villars as synonymous 

 with (E. Bovis. 



Referring to Latreille's account of the genus in Cuvier's ' Rfegne 

 Animal,' he points out some omissions with regard to the habits and 

 oeconomy of (E. Equi and (E. hemorrhoidalis, and objects to the 

 statement that the eggs of the latter are deposited on the verge of 

 the anus of the animal attacked. He strongly deprecates the opi- 

 nion of Pallas and Latreille, that there exists a proper human (Estrus, 

 which he regards as altogether founded in error ; and believes the 

 larva figured in illustration of a supposed case of the kind published 

 by Mr. Howship, to be that of (E. Bovis. 



Lastly, he describes three species, added to the genus (Estrus since 

 the publication of his Treatise, viz. (E. pictus of Megerle, (E. Liby- 

 cus of Riippel, and (E. Clarkii of Shuckard. The following are the 

 characters of the latter species, figures of which, and of (E. Libycus, 

 accompany the paper. 



CE. Clarkii, cserulescenti-fuscus, alls obscuris antice sinuatis basin versus 

 atro-bipunctatis. 



Ilah. ad Caput Bonse Spei. 



He adds also a description of a new species of his genus Cuterehra, 

 with the following characters : — 



C. fonianella, thorace atro lateribus albis, abdomine violaceo : segmentis 



ultimis albis nigro-punctatis. 

 Hah. in Illinois Americae Borealis, cuniculis praecipue infesta. 



