540 PROCEEDINGS OF THE NATIONAL MTJSEXJM vol. in 



ished area (fig. Ill); latter usually impunctate; mesosternum swollen, 

 carinate on basal half or more and with numerous long hairs. 



Metapleuron (fig. Ill): Flattened ; evaporatorium occupying mesal 

 half or more of segment, vaguely or sharply defined from lateral area; 

 latter with or without punctures; osteolar peritreme without a differ- 

 entiated terminal lobe, sharply delimited apically or continued obliquely 

 to anterior margin of segment: osteole opening posteriorly at emargi- 

 nation of peritreme, a subapical spur usually also present. 



Legs: Short to moderately long; anterior tibia (fig. 117) distinctly 

 compressed, dorsal margin with six to ten stout spines, not surpassing 

 tarsal insertion; middle and posterior tibiae (fig. 140) slender, terete, 

 equally spined on all margins ; posterior tibia as long as or longer than 

 abdomen; tarsal II shortest, I equal to or shorter than III. 



Venter: Strongly convex, shining, with or without setigerous punc- 

 tures; posterior margin of each segment finely to distinctly crenulate. 



Type of genus. — Cydnus (Tominotus) signoreti Mulsant and Rey 

 (1866, p. 319), monobasic; of Trichocoris, Trichocoris conformis Uhler 

 (1876, p. 277), monobasic; of Psectrocephalus, Psectrocephalus caecus 

 Van Duzee (1922, p. 271), original designation and monobasic. 



Distribution. — This genus occupies a wide range from North 

 Carolina, Tennessee, Missouri, Arizona, and California south through 

 Central America and the Antilles to Argentina and Chile. 



Discussion. — The separation of this genus from DaUasiellus marks 

 a rather weak area in the present attempt to redefine the cydnid 

 genera that occur in the Western Hemisphere. These two groups are 

 both relatively unspecialized when compared to allied forms and so 

 present no really strong features for separation. The complete sub- 

 marginal row of coarse punctures does set off a group of closely allied 

 species, but leaves the residuum containing species in which the sub- 

 marginal row of punctures varies from absent to well developed and 

 reaching almost to apex of jugum, this character being simply one 

 extreme of an almost continuous variation. 



Tominotus Mulsant and Rey, based on a species originally described 

 from France, appears to be the correct name for this genus as it is 

 the oldest included generic name. A rather unusual set of circum- 

 stances beclouds the soundness of this appHcation, but a statement 

 of events leading to this decision should indicate the reasons for mak- 

 ing it. Tominotus was described in 1866 by Mulsant and Rey as a 

 subgenus of Cydnus and contained the single, newly described species 

 signoreti, that species being the genotype by the monobasic condition 

 of the original proposal. The specimen on which it was based was 

 reported as having come from the collection of Signoret and its lo- 

 cality of capture was given as "Montpellier," in France. The species 

 was thus carried as a European form. However, Signoret (1881b) 



