456 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



vol. 40. 



Fig. l.— Iomus incisus. An- 

 tenna. 



rounded shield of rough black integument; posterior corner some- 

 what excavate to accommodate the antenna; clypeus of thin, trans- 

 parent, white, finely rugulose integument, with four equidistant 

 punctuations below; labium indistinctly tridentate with a trans- 

 verse row of eight small, setiferous punctuations. 



Antennas rather long and slender, but distinctly clavate and 

 strongly geniculate at joint 4; joint 3 slightly longer than 1 and 2 

 taken together; joint 5 the longest, about twice as long as joint 4 

 and about three times as long as 2, 6, or 7. 

 Surface of all the joints densely hirsute with 

 short hairs; joints 4-6 with a single long bristle 

 near the end on the outer face. (See fig. 1.) 

 First segment distinctly narrower than the 

 second, triangular flabellate, the anterior mar- 

 gin rounded, the posterior very oblique on 

 each side, transverse for a short distance in 

 the middle. Anterior half of dorsal surface 

 occupied by 10 radiating areas separated by 

 slightly impressed grooves above and below ; not incised like the other 

 segments. Posterior part of segment above with 10 tubercles 

 arranged in two transverse rows of four and six; anterior tubercles 

 equidistant, posterior with the inner tubercles very close together 

 and the outer remote from the others. 



Second segment with carinas broadened outward to embrace the 

 first segment, anterior margin entire, lateral margin with two deep 

 incisions, posterior margin with two more shallow incisions. Third 

 segment with carinas somewhat broader than 

 the fourth, but with anterior and lateral 

 margins similarly incised. 



Segments with four longitudinal rows of 

 dorsal tubercles, three tubercles to each row; 

 tubercles of two median rows larger and more 

 regularly placed than those of outer rows, the 

 anterior tubercle somewhat enlarged and pro- 

 jecting forward on anterior segments, the 

 posterior tubercle enlarged and projecting fig. 2.-iomus memos, ca- 

 backward on posterior segments. The outer * mM ov SEGMENTS 8 AND 9 - 

 rows well separated from the inner, somewhat curved or oblique, the 

 middle tubercle of the row always largest and somewhat higher up 

 than the posterior tubercle. 



Carinas nearly as broad as the body cylinder, over twice as broad 

 as long; lateral margin with a deep oval incision near the middle; 

 anterior and posterior margins with three or four similar smaller 

 incisions, nearly closed by the connivent angles of the lobes, but 

 with a broad sinus. (Fig. 2.) 



