On a new Hemipferotts Insect forming the type of anew genus. 359 



. We have lately observed the animal ourselves and find it as 

 above described. (Fam. Truncatellidse.) 



Genus Hyala, nobis. 



Head long^ emarginate at the end, forming two lobes. Ten- 

 tacles flat, not clavate at tip, with fine setae at the extremities. 

 Eyes sessile on the centre of their bases. Foot simple behind. 

 Opercular lobe without any caudal cirrhus. Shell hyaline. 

 (Fam. Jeffresiidse.) 

 H. vitrea. 



Genus Hydrobia, Hartmann. 



Opercular lobe small, no caudal cirrhus. Shell covered with 

 an epidermis. Outer lip thin, simple. Animal amphibious. 

 Spins a glutinous byssus during hybernation. 



H. ulvse. H. anatina. H. ventricosa. 



Genus Ceratia, nobis. 



Tentacles flat, rather short, claviform at tip, clothed with long 

 aciculate setae. Foot in front auriculated, behind divided into 

 two long distinct tails. Opercular lobe without a caudal cirrhus. 

 C. proxima. 



Genus Setia, nobis. 



Tentacles pilose. Opercular lobe small, no caudal cirrhus. 

 Foot simple behind. 



S. soluta. S. fulgida. 



S. pulcherrima. S. inconspicua. 



XXXVII. — Description of a new Hemipterous Insect forming the 

 type of a new genus. By W. S. Dallas, Esq., F.L.S, &c. 



[With a Plate.] 



To the Editors of the Annals of Natural History, 



Gentlemen, 



I beg leave to enclose, for insertion in your Magazine, the 

 description of a remarkable new Hemipterous insect from Sylhet, 

 which forms part of a collection made in that country by 

 Messrs. Cotton and Turner. The collection was exhibited at 

 one of the meetings of the Zoological Society, and was very re- 

 markable from the curious manner in which it was arranged, 

 the numerous insects composing it being attached to the bodies 



