464 CLASSIFICATION OF THE RHYKCHOPHOROUS COLF.OPTERA. 



ventral segments are very long, and closely connate ; 3d and 4th 

 short, 5th as long as the two preceding united. The tibiae are 

 truncate at tip, the front ones feebly unguiculate, and with the 

 inner margin of the tip concavq ; tarsi dilated, brushlike beneath, 

 3d jointbilobed in our genera, 4th joint long, claws simple separ- 

 ate; the tarsi are less dilated in some exotic genera. 



The dorsal segments are arranged exactly as in. true Curculion- 

 idaj ; they are all membranous except the last, which is corneous 

 and convex in 9 , divided in ^ : the sides of the ventral segments 

 are only narrowly prolonged upwards, and are imbricated ; the last 

 spiracle is large and uncovered. The elytra have on the inner 

 side the usual lateral fold, but instead of becoming obsolete near 

 the tip, it diverges stronglj'^ from the margin and is continued 

 quite to the suture, fitting to the lateral edge of the last vehtral 

 segments, thus showing an approach to the peculiar modification 

 afterwards seen in Scolytidai. 



!Some of the most curious characters in the Rhynchophorous se- 

 ries occur in tliis famil3\ Among them I may instance Taph- 

 roderus distortus Westwood, from Natal, remarkable by the 

 enormous development of the left mandible ; and Calodromus 

 Mellyi Gueriu, from India, in which the 1st joint of the hind tarsi 

 is as long as the whole bod}^ 



Series III. HETEROGASTEA. 



I have named this series from the fact, that although the abdom- 

 .inal segments are alike in both sexes, and the ventrals also pro- 

 longed upwards at the sides, fitting into a groove on the inner face 

 of the elytra, as in the Allogastrous series, yet the best characters 

 for the separation of the families are to be found in the particular 

 modification of the arrangement of the last ventral segments. 



Nothing distinctive can be predicated of the series as a whole, 

 except the similar pygidium in both sexes, and the prolongation 

 upwards of the ventral segments to fit in the elytral groove. 



The families may be thus distinguished : 



A. Pygidium vertical or declivous : 



a. Auteuuae geuiculate, clubbed; labrnm wanting: 



Last spiracle covered etc. (sub-families etc.) . Calandhid.e. 



b. Auteuuai straight ; labrum distiuct : 



Last spiracle not covered by ventral segments ; pygidium deeply 

 notched to receive sutural apex of elytra. . . Axthribid.e. 



