J. L. LeConte on Rhynchophorous Coleoptera. 41 
ey . 
Arr. IV.2-On the systematic value of Rhynchophorous Coleoptera: 
—an Abstract of a Memoir read before the National Academ: 
of Sciences, at Washington, Jan. 24th, 1867; by Joun 
LECONTE, M.D. . 
In the empirical arrangement of the families of Coleoptera, 
which has resulted from the adoption of the tarsal system of 
division, the families contained in the great natural group of He- 
teromera are followed by the Curculionids and Scolytide, which, 
more or less subdivided into smaller families, have been_sup- 
ed to establish a linear relation between the rostrated Hete- 
romera (Salpingus, Rhinosimus, &c.) to the Cerambycide and 
Chrysomelids, the great types of the Pseudotetramera, or Su 
pentamera, of various authors. 
It is the object of the present investigation to determine the 
limits, and the relations of the first mentioned of these types, 
hora. 
The inforigelty of this type is manifested, not only in the lar- 
val condition by the limited number or absence of visual lenses, 
the want of locomotive appendages, the feeble development or 
entire want of antennz, and the unchitinized epidermis; 
also by the combination in the imago of characters belonging to 
a perfectly developed organism with others pertaining to an infe- 
rior grade in the scale of Coleoptera. 
Thus, for instance, while we perceive in the other series of 
beetles, that the lower forms retain certain larval characters, as 
evidenced by the extension of the coxs, the imperfection of the 
anterior coxal cavities, the softness of the integuments, and the 
want of centralization in the abdomen, all such degradational 
series do not appear in the Rhynchophora, such as vegetative 
growth of the organs of sense, Hipe ooe y pectinate or flabel- 
Am. Jour. Sci.—Srconp Sznres, Vou. XLIV, No. 130,—Juny, 1867. 
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