1911-5 243 



staut ill coloi-iitioii, and can be conveniently gTOuped in a hroad way by 

 tills character, altlioiigli there is the notable exception of L. Jurichis^ 

 Scop. One may also cite the iininaculate form of L. qttadrujnttatns, 

 Pont., as a colour variation, the extensive colour range in the thorax 

 of L. sutiirellus, Duft., and of L. jyusilhis, Gyll., and the red form (v. 

 rufescens, Fowler), of L. jacobssai, Wat. 



Goloiir of suture. — A useful character in conjunction with others, 

 but not necessarily of specific value — cf. the var. thajjsl, Marsh., of L. 

 tabidus, F., the var. poweri, All. of L. gracilis, Kuts., and the various 

 forms of Zi. melanocephalus, de Gr. 



Punctuation. — This character, iisually so valuable in the Coleoptera, 

 admits of extensive but carefully gaiarded use in this genus, at any 

 rate as applicable to the elytra. It may be relied on broadly for group- 

 ing, and more exactly for specific discrimination, and the striate or 

 confused arrangement of the punctuation seems specifically much more 

 constant than its strength, but that this character cannot be universally 

 applied is demonstrated by such species as L. luridus, Scop., L. pusillus, 

 G-yll., and L. membranaceus, Foudr. It is certain, however, that the 

 character, strength, and disposition of the fJwracic punctuation varies 

 so widely within the limits of species as to be — with very few exceptions 

 (e.g., L. sutureUns, Duft.) — of hardly any assistance as a specific 

 criterion. 



Antennse. — The structure of the antennae is probably as constant 

 a morphological feature as any in this group. The relative length, and 

 to a lesser degree the colour is of considerable assistance, but from 

 the comparative length of the separate joints of the antennae we have 

 been able to deduce nothing specifically. 



Humeral a7igles of elytra. — By several authors much stress has 

 been laid on the shape, slope, or angle of the elytral shoulders as diag- 

 nostic of species. It appears to us, however, that these differences are 

 difiicult to appreciate and misleading in application, as the contour of 

 the humeral angles depends very much on the development of the wing 

 muscles, which of course vary as the insect is winged or apterous. 

 Many species, however, are known under liotli forms. The shape of 

 the elytra as a whole, whether oval or oblong in outline, whether fiat 

 or convex in contour, or how far intermediate between these extremes 

 is a character of considerably more importance, and indeed of the 

 greatest assistance in the appreciation of the "habitus" of many of the 

 species. 



An increasing use has recently been made of the shape and 



