GERAUS. 385 
Two males, varying in the curvature of the prosternal spines. An isolated form, 
distinguished by the shining, very sparsely squamose upper surface (the larger pure 
white scales being scattered along the elytral interstices and clustered into small spots 
at their base and apex), the albo-squamose under surface, the rugose, tubulate pro- 
thorax, the long, triangular elytra, &c. 
49, Gerzeus curvispinis, sp.n. (Tab. XV. figg. 21, 21a, ¢.) 
Subrhomboidal, rather dull, the elytra shining, black, the antenne obscure ferruginous; the vestiture very 
sparse, fine, and whitish, a little closer on the under surface and legs and arranged in lines on the elytra. 
Head finely punctate, with a deep transverse groove between the eyes ; rostrum strongly and abruptly 
arcuate from the base, nearly as long as the elytra, moderately stout, sparsely, coarsely punctate, the 
antenne inserted ata little beyond the middle, the antennal club ovate. Prothorax slightly broader 
than long, abruptly narrowed and tubulate in front, the sides rounded anteriorly and gradually converging 
from the base; densely punctate, the narrow interspaces raised into long oblique ridges, the dise with a 
distinct median carina. Elytra triangular, depressed along the suture anteriorly; sharply punctate- 
striate, the interstices flat and asperato-punctate. Beneath densely punctate, the propleura coarsely 
strigose. Prosternum deeply excavate and armed with two moderately long spines, which are directed 
downward at the base and abruptly curved upward towards the tip. First ventral segment broadly 
depressed down the middle. Legs rather elongate. 
Length 44, breadth 2 millim. (d.) 
Hab. Mexico, Cordova (Sallé). 
One male, rather worn. This insect has the prothorax sculptured as in various 
species of Rhyssomatus, the prosternal spines directed downward at the base and 
curved upward from about the middle, and the rostrum long and abruptly arcuate 
from the base. G. curvispinis is nearly related to G. sculpticollis, differing from it in 
the sculpture of the prothorax (the oblique ruge being much more extended), the 
more curved, smoother, and shorter rostrum, the deeply excavate prosternum, the less 
elongate form, finer and sparser vestiture, &c. 
50. Gerzeus tenebricosus, sp. n. (Tab. XV. figg. 22, 22a, ¢.) 
Broad, subrhomboidal, opaque, black, the entire surface very densely punctate, the punctures on the elytra 
transversely confluent and set with minute, narrow, decumbent, fuscous scales. Rostrum a little longer 
than the head and prothorax, stout, the apical half flattened and more slender, coarsely striate-punctate, 
the antennew inserted at about the middle, the antennal club ovate. Prothorax transverse, rounded at 
the sides, constricted and much narrowed in front, with indications of a smooth median line. LElytra 
triangular, narrowly punctate-striate, the interstices broad and flat. Prosternum flattened down the 
middle, armed with two conical tubercles. First ventral segment broadly excavate in the middle 
posteriorly, the suture between it and the second segment strongly sinuate. Anterior cox separated by 
a little less than, the intermediate pair by about twice, their own width. Legs rather short; tibie broad, 
strongly unguiculate, the anterior pair sinuous within. 
Length 52, breadth 3} millim. (d.) 
Hab. Mexico, Tasco in Guerrero (ex coll. Flohr). 
One male. Larger and broader than G. pugnar (Boh.), densely and rugulosely 
punctate above and beneath, opaque, the fuscous vestiture so fine as to be scarcely 
visible at first sight, the prosternum not excavate and armed with two conical tubercles, 
