OOCYCLUS. 638 
depressed sete. Elytra irregularly punctate, bearing indistinct irregular series of 
punctures, and with numerous other punctures, these latter being finer; the seriate and 
subseriate punctures bear rather long sete. Legs rather short, the tarsi very feeble, 
the tibie strongly spinose ; the breast closely and finely punctate-pubescent, the ventral 
segments shining, only very sparingly punctate-pubescent. 
This peculiar insect, of which only a single example is known, is highly remarkable 
from the sculpture and pubescence of the upper surface, these being such as may be 
seen in other families of Coleoptera, but never, except in itself, amongst the aquatic 
Hydrophilide. Although evidently closely allied to 0. brevicornis, it is doubtful whether 
the species may quite agree with it in its structural characters; but the individual is in 
such condition that I fear to submit it to a more detailed examination. | 
2. Oocyclus brevicornis. (Tab. II. fig. 9.) 
Rotundato-ovalis, supra nigro-zneus, nitidus, sublevigatus, prothorace ad angulos anteriores flavescente ; subtus 
vel niger, vel rufescens ; pedibus rufis, antennis palpisque flavis, illarum clava fusca ; elytris punctis minutis, 
‘setigeris, in seriebus sex locatis. 
Long. 13, lat. 13 lin. 
Hab. GuareMata, Rio Naranjo 450 feet, San Gerénimo (Champion). 
Head very finely and sparingly punctate, with an irregular series of more distinct 
punctures along the inner margin of the eye. Thorax nearly impunctate on the middle, 
at the sides sparingly and irregularly punctate, with fine piligerous punctures arranged 
so as to sketch out in an irregular manner the curved series of punctures seen in many 
other Hydrobiini. Scutellum impunctate. Elytra without sutural stria, but with six 
longitudinal series of very fine piligerous punctures, one of which is sutural, and the 
outer is less distinct and regular than the others; these series do not consist of a single 
regular line of punctures, but the punctures are placed irregularly, only extending, 
however, over a very small space in the transverse direction ; along the middle of the 
broad spaces separating these series there are a few very fine piligerous punctures. The 
prosternum is finely carinate along the middle, and in front bears two stout, curved, rigid 
sete or spines, which, however, are easily removed. The colour of the undersurface 
varies from a rufescent to a nearly black tint. 
3. Oocyclus maculatus. 
Ovalis, valde convexus, supra seneo-niger, nitidus, prothorace ad angulos anteriores flavescente, elytris viridi 
maculatis ; subtus rufescens; antennarum basi, palpis, pedibusque flavis; corpore supra sparsim punctato, 
elytris sine punctis seriatis. 
Long. 13, lat. J lin. 
Hab. Guatemaa, Cerro Zumil, 4000 to 5000 feet (Champion). 
Head very short and broad, quite distinctly though rather sparingly punctate. Thorax 
on the disk more sparingly and finely punctate than the head, the punctuation at the 
