PROLYCTUS.—LITHOPHORUS. 487 
Although superficially resembling P. signatus, this insect is much more nearly allied 
to P. dorsalis, from which it is well distinguished by its much smaller size, rufescent 
colour, and narrower thorax. The thorax is marked as in P. dorsalis, but the discoidal 
signature is narrower, and in front its lateral margin is a little more prolonged forwards 
on each side; the two flattened basal tubercles or elevations are approximate, indeed 
almost contiguous. The sculpture of the elytra is almost exactly as in P. dorsalis. 
Only one example was found. 
LITHOPHORUS, gen. nov. 
Antenne articulo ultimo parvo, in articulo decimo quasi recepto. Oculi haud prominuli. Pedes omnes 
distantes. Abdomen absque lineis longitudinalibus. 
The insects of this genus have the characters common to Prolyctus and Bothrideres, 
but differ from both in form and sculpture, also from the former in the absence of the 
so-called coxal lines on the first ventral segment, and from Bothrideres in the form of 
the head, the eyes not being prominent, but placed quite near the thorax. The tibie 
are remarkably broad, and are denticulate externally. 
Judging from the description, the Antillean Prolyctus gemmatus, Reitter, will prove 
to belong to this new genus. It has, like the species here described, the peculiarity of 
bearing a sort of jewel set in the middle of each rough elytron. 
1. Lithophorus gemmifer, sp.n. (Tab. XV. fig. 18.) 
Elongatus, nigricans, supra opacus, rugoso-tuberculatus; prothorace perineequali, anterius utrinque costa 
elevata ; elytro singulo medio bigemmato. 
Long. 6-8 millim. 
Hab. Mexico, Jalapa (Hége). 
Antenne piceous; head scarcely half as broad as the elytra. Thorax oblong, nearly 
straight at the sides, much narrower than the elytra; the surface very uneven, without 
lateral margin, a strongly raised costa extending on each side of the middle from the 
front margin backwards nearly half the length of the thorax; on the middle, extending 
backwards, a longitudinal depression terminated behind by an abrupt, almost furcate, 
elevation; on each side of this latter a deep irregular fovea; at the sides near the 
middle are two acute tubercles; there is no visible punctuation, but a scanty glistening 
flavescent setosity is present. Elytra elongate, striate; the third interstice from the 
suture set with a series of compressed tubercles, the fifth also tuberculate ; each of 
these interstices bears on the middle a translucent yellow tubercle looking like a jewel 
or piece of fine amber ; the outer portions bear some smaller tubercles. Under surface 
coarsely punctate, but shining. Four specimens. 
