1873.] 241 



the tubercles, then slightly widciiecl, and again parallel to the apex ; the second 

 and following segments strongly compressed, giving the abdomen (viewed laterally) 

 an elongate-pyriform appearance. Terebra hardly exscrted. Hind tibife and tarsi 

 incrassated, but less so than in other species of the genus ; ungues simple. Fore- 

 wings with the discoidal transverse vein continuous with the dividing nervtire of 

 the two cubital cells, and hardly geniculated close to its base ; the transverse anal 

 nervure of the hind-wings genticulated in the middle. Both sexes are similarly 

 coloui'ed. The yellow fasciae of the abdomen are paler after the second segment ; 

 continued, but narrower, under the belly. Coxae shining black ; trochanters yellow ; 

 femora and tibiae reddish-yellow ; the hiud femora with an apical black streak beneath. 



The abdomen is sliorter, stouter, and more pyriform than in other 

 large species. The black and yellow coloration are suggestive of Ban- 

 clius, but the absence of the areolet corrects the impression. The neu- 

 ratiou of the wings, as indicated above, is peculiar, and might be taken 

 as constituting a new genus, of the same value as Agrypon and others. 

 The specimen above described, which Mr. Smith has kindly given to me, 

 is a $ , but I have seen one or more males of it in the British Museum. 

 They were bred by Mr. Mitford, from a supposed permanent variety of 

 Lasiocampa frifolii, and are not only new to Britain, but hitherto 

 unknown anywhere. 



I am also favoured by Mr. Smith with the following information 

 respecting a fine Mesostenus, hitherto undescribed, in the British 

 Museum. Perhaps this notice may serve as a guide to any collector 

 who may be fortunate enough to meet with the same species in the 

 north of England. Five specimens were purchased by the Museum 

 at the sale of the late Mr. Hey sham's collection. They attracted the 

 notice of the late Mr. Desvignes, who intended to describe them, but 

 unfortunately did not. They were taken in the neighbourhood of 

 Carlisle, as were also four specimens of Trigonalys angUcana, one of 

 which was sent to Mr. Smith for identification. The following is that 

 gentleman's description of the Mesostenus, which I propose to name 



Mesostenus MArRUs, sp. n. 



" Totally black, excepting the scutellum, which is yellow, as well as six joints 

 " of the middle portion of the antennae. The anterior tibiae, and the apical portion 

 " of the femora, are ferruginous ; the anterior tarsi obscurely so. The extreme apical 

 " margin of the fii-st segment of the abdomen is sometimes obscurely ferruginous. 

 " Metathorax truncate, armed laterally with two acute spines. Long. 5 lines." 



I have seen, but never examined, the specimens, and my impression 

 is that they are of large size for the genus. 



St. Albans : February, 1873. 



