12 



RHYNCHOPHORA OF NORTH EASTERN AMERICA. 



Itlujccrus, which have been variously placed in consequence by 

 different authors. In the Breuthidoe, apart from the sexual dis- 

 parity in the mandibles, sufficient alone to indicate their anomal- 

 ous character, the lack of a gular peduncle, with the mentuin con- 

 sequently nearly filling the buccal cavity, indicates a type of sep- 

 arate origin. In Calandrinae also we observe remarkable de- 

 partures from the usual form, the gular peduncle being extremely 

 long and narrow, while in Cossonina? it is present as a broad 

 short plate. 



The difficulty attending the observation of these mouth parts 

 is fortunately in great part obviated in classification by the fact 

 that modifications of the more readily observed antenna? serve 

 as equivalent indices of relative rank. The most simple form of 

 antenna is found in the Brenthidae, which therefore, in conjunc- 

 tion with what has already been recorded of their mouth parts, 

 leads us to place them first or lowest in the series. Their an- 

 tennae are straight, without a definite club at apex and the last 

 three joints are not greatly different in length. (Fig. 12, A.) 



Fig. 12. A, antenna of a Brenthid, Eitpsnlis mitiuta Drury; B, antenna of Rliiiw- 

 maccr ; C, antenna of an Anthribid, Euparins inaniioi'ciis Oliv. (Original.) 



The next step is found in Rhinomaeerina? and Anthribida? 

 (Fig. 12, B. and C.), already noted for their comparatively flexi- 

 ble palpi. The antennas are straight in these groups and the last 

 three joints preserve their relatively equal length, but are en- 

 larged to form a loose club. The entire antenna is also more 

 pubescent ami presumably sensitive. 



The next step in autennal development is the shortening of 

 the last three joints with more or less modification of their shape, 

 so that a compact oval or globose club results. The three joints 

 are, however, plainly separated by sutures and are pubescent and 

 nearly equal in length, the terminal one being sometimes elongate. 

 Such clubs are found in the subfamilies Apionimo, Allocorhyninse 



