PROC. ENT. SOC. WASH., VOL. 20, NO. ">, MAY, 1U1S 109 



Mexico, was the first species of the genus to be described from the 

 United States, though Uhler placed it in Hhyparochromus and 

 Van Duzee has transferred it to Aphcinux. I now add three other 

 species from the United States from material in the U. S. National 

 Museum. 



A. Claval suture present. Membrane never wholly absent. Larger 

 species, for the most part dark castaneus and pilose. 

 B. Pronotum wider than long; anterior lobe not elevated; anterior 

 angles behind eyes rounded. Head not sunk to the eyes. Scutel- 

 lum finely punctuate. (P. Americanus Van D) compactus Uhler. 

 BB. Pronotum subquadrate; anterior lobe swollen; anterior angles 

 forming a distinct angle. Head sunk to the eyes. Scutellum 

 almost impimctate, i inlc.nlnlus n. sp. 



AA. Claval suture absent; clavus connate with corium. Membrane 

 absent, Sjnaller species, for the most part, pale castaneus or 

 ochraceous. Anterior angles of pronotum rounded. 



C. Lateral margins of pronotum paralles sided. Apical mar- 

 gin of the corium lightly concave. Abdomen with three or 

 four long setae posteriorly on each side. Pale castaneus and 

 ochraceous loiiiiixcltixus n. sp. 



CC. Pronotum widened anteriorly. Apical margin of corium 

 straight. Abdomen with a few shorter setae posteriorly 

 ochraceous pallidusn.Bp. 



Plinthisus compactus Uhl. 



Rhyparochromus compactus Uhler, Proc. U. S. Nat. Mus. XXVII, 354, 

 1904. Aphanus compactus Uhler, Van Duzee, Check List of Hemiptora, 

 23, 1916; Catalogue, 195, 1917. 



Plinthisiix <nitc.ric(i><.its Van Duzee, Trans. Amer. Entomol. Soc. XXXVI, 

 75, 1910. 



I have examined the female specimen which Uhler described in 

 the U. S. X. M., collected by H. G. Barber at Las Vegas Hot 

 Springs, N. M., labeled ('o-type No. 6849 and carefully compared 

 it with a female specimen of Van Duzee's americanus from Tyngs- 

 boro, Mass., presented to me by Prof. H. M. Purshley. These 

 are identical but the rather inexact color description by Uhler 

 misled Mr. Van Duxee and other Hemipterists. The Las \'eg;ts 

 specimen fits the description of americanus, being dark shining 

 castaneus on the head, anterior lobe of the pronotum, scutellum. 

 central disk of corium and heneath, the remaining part- are paler. 

 as described by Van Duzee; the last two segments of the antennae 

 piceous. 



Plinthisus indentatus n. sp. (Ms. name of I'hler. 



Shining, sparsely pilose. Head, anterior lobe of pronotuin and pro- 

 sternum castaneus: scutellum. posterior disk of corium. meso and nieta 



