CENTRINOIDES.—PSEUDOCENTRINUS. 325 
both Centrinites and Linmobdaris. The form of the mandibles is peculiar: the left 
one, which is placed uppermost when they are closed *, is so deeply notched as to 
appear bidentate externally, and the right one is small and angulate externally. The 
tarsal claws are approximate at the base, Centrinotdes in this respect approaching 
Zygobaris, Lec., and its allies. 
1. Centrinoides ciliaris, sp.n. (Tab. XVII. figg. 5, 5a, 6, 3.) 
Subopaque, black ; sparsely clothed above and beneath with short, very fine, hair-like, cinereous scales, those 
on the elytra a little coarser, setiform, and arranged in a single line down each interstice, the tibie 
thickly set with short brown hairs at the apex within. Head closely punctate, shallowly foveate between 
the eyes; rostrum arcuate, rather stout, about as long as the head and prothorax, coarsely serlate- 
punctate, longer, smoother, and a little more slender in the 9, the antenne inserted at about the 
middle. Prothorax broader than long, rounded at the sides from near the base, feebly constricted and 
much narrowed in front ; coarsely, densely punctate, with indications of a smooth median line. Elytra 
gradually narrowing from the base, coarsely punctate-striate, the interstices flat, very little wider than 
the strie, and each with a single series of coarse deep punctures. Beneath coarsely, closely punctate. 
Legs rugosely punctate. 
g. Prosternum armed with two long, or moderately long, porrect spines, which are bent downward at the 
tip in fully-developed specimens, and with a very deep circular excavation between them; anterior 
tibize closely ciliate within. 
@. Prosternum with a broad, shallow, posteriorly evanescent, median sulcus. 
Length 43-5, breadth 24-23 millim. (¢ 2.) 
Hab. Mexico, Ventanas in Durango (Hége). 
Three males and two females, the males varying in the development of the pro- 
sternal spines. Easily recognizable amongst its allies by the single series of coarse 
punctures down each elytral interstice and the very fine scattered vestiture. 
PSEUDOCENTRINUS, gen. nov. 
Rostrum stout, arcuate, moderately long; mandibles stout, almost straight on their inner edge; antennal 
club ovate; prothorax feebly constricted in front, broader than long; seutellum free; elytra a little 
wider than the prothorax, narrowing from the rounded humeri; pygidium large, transverse, convex, 
vertical, and fully exposed in the ¢,, not visible in the 2; prosternum unarmed, sulcate ; anterior cox 
narrowly separated ; ventral segment 5 transversely tumid in the middle in the 2 and sinuato-truncate 
at the apex in the ¢, 3 and 4 very short; femora unarmed ; tarsal claws divergent; body elongate- 
or oblong-rhomboidal, squamose. 
Type, Centrinus ochraceus, Boh. 
This genus is related to Centrinogyna, Casey, which also has a large exposed 
pygidium in the male}, but may be known from it by the sulcate prosternum, the 
differently-shaped body, &c. The type of Pseudocentrinus is not unlike Gereus 
senilis, but the other species have a very different facies. Ps. ochraceus and Ps. hybrida 
agree in the relative lengths of the ventral segments ; but the fifth is shorter (especially 
in the 2 ) in Ps. deceptus. 
* They have been reversed by our artist on the Plate. 
+ The female only of one of the two species described by Casey has been examined by me. 
