THE ENTOMOLOGIST. 



No. 21.] NOVEMBER, MDCCCLXV. [Price 6d. 



Notes on the Genus Hister. By G. R. Crotch, Esq. 



The admirable Monograph of M. de Marsenl on this 

 group, begun as long ago as 1854, and accom))anied with 

 figures of every species, has considerably popularized the 

 study of this somewhat difficult group. Their singular same- 

 ness in appearance doubtless deters many, but when once the 

 complicated variation in their striae and punctuation, and the 

 beautiful characters afforded by the under side, are fairly 

 comprehended, they no longer seem wearisome. Some lati- 

 tude, however, must be given to the descriptions of striae, 

 &c., for they are by no means cast in the same mould ; some 

 indeed, as Saprinus nitidulus, vary exceediugly. In the true 

 Histers, to which I wish now more particularly to direct 

 attention, the principal characters of value are the stride on 

 the elytra and the thorax. Ou the former, in H. bissexstria- 

 tus for example, are six perfect stria3, which are termed the 

 first, second, &c., dorsal counting from the shoulder, the last 

 being called the sutural. The fointh, fifth, and sutural are 

 very generally abbreviated. In addition to these, however, 

 a most important stria exists, iiamely, at the margin of the 

 elytra, outside and parallel to the first dorsal : this is the sub- 

 humeral stria of M. de Marseul, and is used by him to divide 

 the species into groups. When it is entire and closely 

 parallel to the first dorsal, it is termed the internal sub- 

 humeral stria, and is occasionally broken, the continuation 

 starting at a different point, and being more like an append- 

 age to the real stria. The external subhumeral stria is fur- 

 ther removed from the first dorsal at its origin, and subse- 

 quently has a marked angulation in its course. The thorax 

 has one or two stria) at the sides. The subhumeral stria 

 must not be confounded with the small oblique plica visible 

 at the humeral angle of most Histers. 



VOL. II. X 



