80 ]\Ir. D. Sharp on some 



been unable to see any difference of importance between 

 the two, and the insertion of the antennae in this sex is 

 likewise extremely similar. It is true that the upper 

 surface of the prothorax in Aglycyderes setifer is differen- 

 tiated, although somewhat indefinitely, fi'om the flanks by 

 a series of projecting serrations, and that in Proterliinus 

 nothing but the rudiments of such a separation are to be 

 detected, but I am unable to consider this as of extreme 

 importance; for in Ayh/cyderes Wollastoni the sepai'ation 

 alluded to is considerably more indefinite than it is in 

 A. setifer ; while, on the other hand, although such sepa- 

 ration is excessively rare in the Rhyncopliora, yet it is 

 sometimes distinct, and, in fact, I have before me, as I 

 write, a highly-peculiar genus o^ AnthribldcB (belonging, 

 therefore, of course to the Rhyncoplwra), in Avhich this 

 lateral border is as highly developed along the whole side 

 of the prothorax from the anterior to the posterior angles, 

 as it is in the average of the Coleoptei^a, and far more than 

 it is in Aglycyderes. Again, there exist, as stated by 

 Leconte, in Aglycyderes setifer slight traces of two pro- 

 sternal sutures, extending outwards from the front coxal 

 cavities; but yet in A. Wollastoni I fail to trace them 

 more certainly than I think I can in Proterliinus vestitus ; 

 and in AnthribidcB sutures extending from the coxal cavi- 

 ties to the sides of the thorax may often be seen much 

 less obliterated. On the other hand, 1 quite fail to see 

 anything in the structure of the head and thorax in 

 Aglycyderes which does not accord with Dr. Leconte's 

 definition of Rtiyncophora, viz., " Rhyncophorous Cole- 

 optern are those in which the posterior lateral elements of 

 the head and prothorax coalesce on the median line of the 

 imdersurface of the body, so as to unite by a single 

 suture." (Proc. Am. Phil Soc. XV. 1876, p. xi.) 



Nevertheless there does exist an important difference 

 between Proterliinus and Aglycyderes, as to the direction 

 which the sexual differentiation of the head has taken. 

 In one of the sexes of Proterliinus the head is elongated 

 in front into a well-marked beak, while in that sex of 

 Aglycyderes in which the head is most extended, the 

 extension is rather in the transverse than in the longi- 

 tudinal direction. AVhen we recall how persistent a 

 character the beak-like extension of the head is in the 

 Rhyncophora — existing in a well-marked form in all the 

 species except in certain Antlirihidoe. — much importance 

 must clearly be attached to this character. 



