MALACOKHINUS. 



585 



6. Malacorhinus sericeus. 



Ovate, convex, testaceous; thorax rufous or testaceous, impunctate, with a silky gloss ; elytra very minutely 

 punctured, each with two spots at the base, two below the middle, and one at the sides, black ; tibiae and 

 tarsi fuscous. 



3 ~ Elytra with a small oblong fovea at the sides. 



Length 2| lines. 



Eab. Guatemala, Chiacam, Senahu (Champion) ; Nicaragua, Chontales (Janson), 



At first sight M. sericeus seems to be scarcely separable from M. decem-punctatus, 

 which it resembles exactly in the number and position of the elytral spots. It differs, 

 however, as follows : — the thorax is not nearly so constricted at the base, and its surface 

 is entirely impunctate and silky in appearance ; the two posterior spots on the elytra are 

 placed immediately behind the middle, and not so far back as in M. decem-punctatus ; 

 and, lastly, the elytral fovea of the male is small and has no tubercle within. Specimens 

 from Chontales are redder in tint, and are more convex in shape and more widened at 

 the middle, than those from Guatemala. The first two joints of the antennae are 

 generally testaceous, the other joints fuscous. 



7. Malacorhinus biplagiatus. (Tab. xxxni. fig. 20, * .) 



Black, above reddish-fulvous ; head and thorax impunctate ; elytra very finely punctured, each with a round 



spot near the scutellum, and a transverse one below the middle, black. 

 cJ . Elytra widened towards the middle, each with one or two tubercles near the lateral margin, the tubercles 



followed by a narrow elongate fovea. 

 Var. Elytra with the black spots enlarged and connected, leaving a central spot and the apices fulvous. 



Length 2-2| lines. 



Head with the frontal tubercles and the clypeus narrowly transverse and distinctly raised ; antenna? black (the 

 basal joint often fulvous), the third joint slightly shorter than the fourth ; thorax subquadrate, distinctly 

 narrowed at the base, the surface (when seen under a very strong lens) very finely punctured ; scutellum 

 fulvous ; elytra scarcely more distinctly punctured than the thorax, each with a round spot near the 

 scutellum, and a more transversely-shaped one below the middle, black ; underside and legs black. 



Eab. Mexico, Ventanas (Edge), Capulalpam, Yolotepec, Cordova, Juquila, Yolos, 

 Oaxaca (Salle) ; British Honduras, R. Sarstoon (Blancaveaux) ; Guatemala, Capetillo, 

 Zapote (Champion). 



The male of M. biplagiatus is of a more widened shape towards the middle than the 

 female, and may be known by the conical tubercle placed at the centre of (and a little 

 within) the lateral margin of the elytra; this tubercle is often preceded by a shallow 

 fovea and followed by a deeper one ; in front of the latter the lateral margin seems 

 doubled, enclosing a narrow and elongate depression. In an example from Yolotepec, 

 which I refer to the same species, the disc of the elytra is black, enclosing a subquadrate 

 fulvous spot at the middle, and the lateral margins and the apices are fulvous. Another 

 specimen (a male) from Yolotepec differs from the type in having a narrow transverse 

 band at the base of the elytra, this band being connected at the sides with a broad band 

 placed below the middle ; in this example the elytra have two tubercles placed near 



biol. CBKTE.-AMEE., Coleopt., Vol. VI. Pt. 1, January 1888. 4 f 



