HETEROMERA. 81 



On flowers of white-thorn, &c. ; it has also been bred from woody excrescences 

 on the trunks of birch trees; common and generally distributed throughout the 

 kingdom. 



The chief season for the genus appears to be at the end of May and 

 the beginning of June, when the white-thorn is in blossom ; in fact all 

 blossoming trees appear at this season of the year to attract certain of the 

 species in profusion. 



RHIPIDOPHORID-E. 



About fifteen genera and one hundred species belong to this genus ; 

 they are widely distributed throughout the greater part of the world, 

 both in tropical and temperate countries, and range from Siberia to 

 South Africa, India, and Brazil ; seven genera represented by thirteen 

 species occur in Eurgpe, of which one only is found in Britain; the 

 family forms the second group of Mulsant's Longipedes, the first group 

 being the Mordellides ; some authors have included them in a tribe 

 under the family Mordellidae ; certain of the genera are in the larval 

 state parasitic upon Hytnenopterous insects, and Rhipidiu* pectinico /?>, 

 a continental species, is parasitic on the orthopterous Blatta germanica, 



The following are some of the chief characteristics of the family : 

 Elytra narrow and acuminate, strongly divaricate at apex, not covering 

 the wings ; head vertical, strongly constricted behind eyes, which are 

 oval and entire; antennae 11-jointed (except in certain females in which 

 they are 10-jointed), pectinate or flabellate in the males, often serrate in 

 the females; thorax as broad at base as elytra ; scutellum hidden or almost 

 hidden ; mesosternum short, metasternum large ; legs, as a rule, long, 

 anterior coxae large, conical, and contiguous, spurs of tibiae usually dis- 

 tinct ; claws bifid at apex. 



METCECUS, Gerstft. ker. 



This genus contains only one species, which has by some authors 

 been included under Rhipidophorus (Rhipiphorus) ; it appears to be 

 very variable, no less than nine varieties being mentioned by Heyden, 

 Reitter, and Weise in the last European catalogue. Besides the 

 characters above given the following may be mentioned for the genus : 

 Head small, deflexed, almost flat on its upper surface, antennas inserted 

 on small frontal protuberances between the eyes, which are small ; 

 thorax very deeply and broadly channelled in centre, and produced at 

 base into a very strong lobe which covers the large scutellum ; inter- 

 mediate coxae distant ; anterior tibiae without distinct spurs ; tarsi 

 longer than the tibiae, with large bifid claws ; abdomen with six visible 

 ventral segments ; the larva of M. paradox it* is found in the cells of 

 wasps' nests, and it is probable that the female deposits her eggs in the 

 already formed cells, her abdomen being long and acuminated and suited 

 to the purpose. 



VOL. v. ' o 



