Z KHysrCHOPHORA. 



regard to the last-named instance, Dr. Gaban informs me that 

 he has since ascertained that when the two gular sutures are 

 present in the Platypodix.i;, the character is a serual one, the 

 sutures uniting in the female, while in the male they are con- 

 tinued independently to the hind margin of the head. 



In the case of the prosternum, the points which are specially 

 characteristic of the Ehynchophora are the disappearance of the 

 two sutnres that separate the prosternum (the central piece 

 before the front coxae) from the side-pieces or plein'a3, and the 

 fusion of the epimera in the middle line behind the coxae. To 

 both of these characters there are exceptions. The prosteriial 

 sutnres are present in the Riiinomaoehin.e, and traces of them 

 near the coxae can be observed in many genera of Curculionid^ 

 (fig. 7). As regards the fusion of the epimera, the only apparent 

 exceptions in the suborder known to me are the African Cur- 

 culionid genera HopUtotrachelus, .Schh., and Biirsoj^s, Schh., which 

 comprise the subfamily Bybsopin.i;. In these insects, if examined 

 externall)', the epimera appear to be separated by an appreciable 

 interval ; but if the prothorax be removed and examined in- 

 ternally, it will be found that the posterior portion is fused into 

 a solid ring without any trace of a suture. 



In the other suborders of Culeoptera the prosternal epimera 

 are separated, with a few exceptions, such as the Megalopodid^ 

 among the Phytophaga, Cossyplms and Endostomus (Tene- 

 BRiONiD.i:), certain Lagriii).!;, and the genus JVemaiidium among 

 the CucuJiD.E ; but in none of these insects are the pieces fused 

 together as in the Kliynohophora. 



Various attempts have been made to subdivide the Ehyn- 

 chophora into a number of families, the new families proposed 

 having been for the most part extracted from the Ccrculioxid.i:. 

 But those authors who have gone furthest in splitting up this 

 family liave made no special study of these insects as a whole, 

 and when the attempt is made to apply their classifications to 

 faunas with which they were not well acquainted, the results 

 have proved far from satisfactory. In the present state of our 

 knowledge, therefore, it seems preferable to follow Lacordaire, 

 David Sharp and Ganglbauer in recognising only the four main 

 families, Anthribid,^, Curculionid.s:, ScoLYTin.E* and Bken- 

 THiD.i, together with the two small and highly aberrant groups, 

 Peoterhixii»,e and Aglyctderid^, which do not occur within 

 our limits. 



Owing to the presence of various convergent forms, it is not 

 easy to lay down hard and fast lines of demarcation between 

 several of these families, but the following key will perhaps assist 

 in their discrimination. 



* There does not appear to be any nistification for the use of tlie name 

 Ipid.e for this family, as Scolytus, Mull., is a valid genus. 



