LeConte.] 



CALAISTDKID^. 329 



obsolete. The space between the ridge and the margin has a pearly lustre, 

 and may pvossibly serve as a stridulating organ; in the Consoniaa; this ridge 

 diverges much less and becomes obsolete sooner. 



Abd(Mnen with five ventral segments, of which the first and second are 

 longer, witli the suture nearly obliterated at the middle in Calandrida;, 

 but deep and entire in Rhinidte; in Cossonidm they are very long, and the 

 suture is effaced at the middle; the third and fourth segments are short, and 

 the sutures straight and deeply impressed; the fifth is about as long as the 

 third and fourth united, and is rounded behind. The dorsal segments are 

 membranous, except the last, or pygidium, which is large, nearly [lerpen- 

 dicular in Calandridm, obliquely deflexed in the other subfamilies; the 

 anal segment of the (^ is quadrate and retractile in Calandridm and BM- 

 nid(P, broader and less retractile in Cossonidw, but not continuous with the 

 pygidium as in GurcuUonidcB and Brenthida;the lateral edge of the meta- 

 thorax and of the ventral segments is sharp and fits into the lateral groove 

 of the i.iner surfiice of the elytra; in the Cossonidw this edge continues on 

 and around the last ventral, thereby showing a tendency towards the modi- 

 fication finally perfected in the Scoli/tidw, and of which we have already 

 seen trac>^s in the Brenthido'. 



Legs moderate, varying though not greatly, according to genus; thighs 

 usually stoutly clavate, not toothed; tibioe rather short, strongly unguicu- 

 late at the outer angle. Tarsi frequently narrow and not brush like be- 

 neath; third joint sometimes bilobed, (Bhinidce) sometimes broad patellate, 

 and not emarginate, (certain Splienophori); claws divergent, simple. 



I have embraced in this family several very distinct forms which agree 

 with Curculionidce in general characters, but differ in having the genital 

 segment of the (^ not articulated directly at the end of tlie last dorsal, but 

 either retractile or concealed under it. While the mouth organs of the Cos- 

 sonidm are similar to those of ordinary Curculiomdcv, and submit to modi- 

 fications similar to those of Hylobiini for instance, in the other subfamilies 

 there are specializations which do not otherwise occur among Rhynchophora. 



With regard to the affinities of the members of this family, it may be said, 

 in general terms, that the Calandridce show an alliance with the Barini; 

 the Rhinidm continue the specialization still farther, and have not a direct 

 resemblance to any other tribe. The Cossonidm seem to be a connecting 

 line from Hylobiini to Scolytidm, to which they approach very closely in 

 Rhyncolus. 



Three subfamilies occur in our fauna, the characters of which have been 

 sufficiently indicated above: the following table will enable them to be 

 readily distinguished. 



Buccal cavity elongate, peduncle of mentum elongate, 



narrow: pygidium exposed CALANDRIDA. 



Buccal cavity entirely at the apex of the beak; py- 

 gidium covered RHINIDJE. 



Buccal cavity normal, peduncle of mentum short, oral 



organs exposed; pygidium covered COSSONIDM. 



PROC. AMER. PHILOS. SOC. XV. 96. 2p 



