114 Mr. W. S. Dallas's Note on Acanthosoma. 



This species varies greatly in colour, but is easily distinguished 

 from the other species of the genus by the form of its head, and 

 by its having the projecting margins of the abdomen banded with 

 black and yellow or orange. The green specimens generally have 

 a reddish band across the posterior margin of the thorax, and the 

 coriaceous portion of the elytra more or less tinged with red ; the 

 brown clouds of the membrane are frequently very indistinct. 



This species is evidently the true Cimex griseus of Linnaeus, 

 both according to his descriptions and the specimens preserved in 

 his cabinet. Nevertheless the name has been applied by most 

 authors since his time to the Cimex punctipennis of Illiger, an in- 

 sect of much larger size belonging to the genus Rhaphigaster. 

 This error has probably arisen, in a great measure, from the care- 

 less manner in which Fabricius has given the synonyms of his 

 C. griseus ; for he quotes as belonging to that species the C. gri- 

 seus of Wolff and Panzer, which represent Rhaphigaster punctipen- 

 nis, and also the Cimex Betulce of De Geer, which agrees precisely 

 with the true C. griseus of the Linneean cabinet. This error has 

 been to a certain extent rectified by Amyot in the " Annales de la 

 Societe Entomologique de France," where he quotes Cimex griseus 

 Fab., Wolff and Panzer as synonyms of Raphigaster punctipennis, 

 stating particularly that it is not the same insect as the Cimex 

 griseus, Linn., but afterwards again quotes them in giving the 

 synonymy of the present species. 



I have placed the Cimex inter stinct us, Linn., as a synonym of this 

 species, although the insect to which that name is attached in the 

 Linnaean cabinet is a specimen of A. dentalum ; for Linnaeus states 

 particularly in the Fauna Suecica that the margins of the abdomen 

 are banded with black, which is the case in no species except A. 

 griseum. The description given by Linnaeus in the above work 

 agrees precisely with specimens of A. griseum in the British 

 Museum collection, but cannot by any means be made to suit the 

 insect to which the name is attached in his own. 



