111 
distinctly punctured, and there are two irregular fovez on each side 
of the middle, rather nearer to the mesial line than the outer margin. 
The elytra are one-fourth longer than broad ; the apical portion is 
moderately produced and somewhat pointed: the whole upper sur- 
face of the elytra is covered with very minute ruge, and there are 
moreover some minute tubercles; on the outer half of each elytron 
is a series of transverse furrows, with convex interspaces equal in 
width to the furrows. 
Nycrexia Saunpersu. Nyct. atra, oblongo-ovata, nitida ; thorace 
punctato ; elytris sulcis transversis pauld irregularibus a margine 
laterali usque ad medium ductis. 
Long. corp. 74 lin. ; lat. 4 lin. 
Hab. Bahia Blanca. 
Head distinctly punctured in front. Thorax rather coarsely punc- 
tured, excepting on the disc, which is almost impunctate ; emargi- 
nated in front, the emarginated portion in the form of a segment of 
a circle; the lateral margin slightly rounded. The hinder part of 
the thorax and the middle are equal in width ; the fore-part is shghtly 
contracted. The elytra are ovate, and but little convex ; they are 
depressed at the suture, most distinctly so near the scutellum. The 
lateral keel is very prominent, and extending from this keel to the 
middle of the elytron are distinct transverse furrows, the interspaces 
of which are convex, and about equal in width to the grooves. The 
apical portion of the elytra is moderately produced. The three basal 
segments of the abdomen, as well as the metasternum, are covered 
with slightly irregular longitudinal ruge: the terminal segment is 
punctured. The prosternum and mesosternum are coarsely punc- 
tured, and the punctures are confluent. 
This is a small species compared with N. Jevis (being about the 
size of N. nodosa) ; its form is more elongated and much less convex. 
The lateral margins of the thorax form an even curve from the front 
to the back. 
The specimens from which the above description is drawn up were 
found by Mr. Darwin in the month of September, on the sandy 
plains of Bahia Blanca. 
Nycrewia rugosa. Nyct. nigra, opaca, ovata; thorace distinct? 
punctato ; elytris valde rugosis, sulcis duobus, suturam prope, lon- 
gitudinalibus et interruptis, impressis. 
Long. corp. 73; lat. 43. 
Hab. San Blas (near Rio Negro) and Bahia Blanca. 
This, which is a small species compared with N. levis, approaches 
that species in general form, but the thorax and elytra are less con- 
vex. The head is coarsely punctured in front. The thorax is coarsely 
punctured, and the punctures are numerous, excepting on the disc : 
a groove runs parallel with and close to the margins, but at the 
posterior margin it is interrupted in the middle. The elytra are 
convex, and of a short ovate form, and the apical portion is but little 
produced ; their width is about one-fifth less than the length: the 
whole upper surface is covered with coarse and very irregular ruge. 
