708 On Aquatic Carnivorous Coleoptera or Dytiscide. 
varieties may prove to be good species; the sexual characters of male and female 
distinguish it amply from the following ones. 
In Mexico the females appear to be usually nearly or quite destitute of sexual 
sculpture. 
South America to Mexico ; Bahia (Castlenau) ; Santa Cruz, 10 to 17, 10, 1872, Van Volxem ; Panama, 
Chontales, Mexico. 1103. 
1107. Megadytes fraternus, n. sp.—Ovalis, sat latus et convexus, anterius angus- 
tatus, capite anterius prothoraceque ad latera anguste testaceis, elytris versus 
apicem obsolete ferrugineo-maculatis, subtus nigricans pedibus quatuor anterioribus 
rufis, tarsis intermediis picescentibus, pedibus posterioribus nigro-piceis ; antennis 
vracilioribus. Long. 223, lat. 13 m.m. 
The front tarsi of the male are large, attaining nearly 3 m.m. in the transverse 
direction, their claws are elongate, the front one being conspicuously longer than 
the other; on the undersurface the palettes are broad, the basal fringing hairs are 
stout and elongate, and at the heel diverge distinctly but not greatly from the 
palettes ; the pubescent area has a great extension in the transverse in comparison 
with the longitudinal direction. The intermediate tarsi bear elongate sexual 
pubescence on the three basal joints. The female has the thorax more dull than 
the male, and the elytra show a highly developed and beautiful sexual sculpture, 
consisting of very short but regular rectilinear impressions covering the whole 
surface, except on a quite small space at the apex. 
This species is variable, or rather perhaps will prove to be one of several closely 
allied species ; what I have decided to treat as varieties being in that case really 
distinct species. 
In Guadeloupe and St. Domingo the sculpture in the females does not reach 
quite to the lateral margin. In Surinam and Demerara a very large variety occurs, 
with the male tarsi very highly developed. The type above described by me is 
from Panama; and in the more southern parts of South America the sexual 
characters appear to be not quite so highly developed. 
Panama; Guatemala (Duenas, G. C. Champion), Guadeloupe, St. Domingo, Demerara. 1104. 
1108. Megadytes steinheili, Wehncke (ex parte) Stet. Ent. Zeit. xxxvui, p. 359.— 
Ovalis, latiusculus, anterius minus angustatus, capite anterius prothoraceque ad 
latera anguste testaceis, elytris versus apicem obsolete ferrugineo-maculatis ; subtus 
nigricans, pedibus quatuor anterioribus rufis, tarsis intermediis picesentibus, pedibus 
posterioribus nigro-piceis ; antennis gracilioribus. Long. 23, lat. 133 m.m. 
This species is very closely allied to M. fraternus, but is broader in front, and the 
sexual characters are even more highly developed, and the shape of the male tarsi 
