1336 COLEOPTEEA 



Stygnohydrus. 



Nov. gen. 



Body very convex, oval, nearly glabrous above. Antenna 9-arti- 

 culate, basal joint elongate; second short, subrotundate ; joints 

 3-5 small and slender, sixth small and very transverse ; club three- 

 jointed, moderately large, its basal joints transverse. Maxillary 

 palpi short, the penultimate joint shorter than those next to it. 

 Mentum plane. Labrum slightly emarginate, separated from the 

 forehead by a rather broad and deep transverse groove. Prosternum 

 concave, scooped out in fact, without a central carina or process. 

 Front coxa elongate and transverse, almost touching each other. 

 Mesosternum with a perpendicular lamina or process in front, carini- 

 form above, capable of projection between the anterior coxae. 

 Metasternum very short, its frontal process extremely narrow and 

 subdepressed ; its hinder portion a little elevated in the middle, 

 triangular, forming an acuminate process w T hich extends about half- 

 way between the nearly contiguous posterior coxae. Epipleurce 

 remarkably narrow throughout. Intermediate coxa only slightly 

 separated. Femora broad, grooved below, all distantly but dis- 

 tinctly punctate and pubescent underneath. Tibia a little incurved 

 along the inside, with straight terminal spines ; the anterior with 

 apical hooks, and, on the outside, near the extremity, with a spini- 

 form process. Tarsi with yellow setae, the second joint of the 

 posterior rather longer than the first. The abdomen, in the only 

 specimen available, is concealed or retracted under the meta- 

 sternum, but I think I can see a median carina on the basal 

 segment. 



The type is an interesting little insect which has the appearance 

 of a small Morychus ; the prosternum is not unlike that of a Cyphon : 

 on the whole it is more nearly related to Tormus than to any other 

 known genus of the Hydrophilidce. 



2343. S. ni.tid.US, n.s. Glossy, aeneo-niger, paler behind ; legs 

 reddish, the tarsi, palpi, and antennae yellowish ; club opaque, 

 fuscous, densely pubescent. 



Head distinctly but not closely punctured. Thorax large, re- 

 motely and moderately finely punctured. Scutellum triangular, 

 minutely sculptured. Elytra irregularly, rather distantly, and 

 moderately finely punctured on their basal portion ; along the sides, 

 and behind, the punctures become coarser and serial ; the hinder 

 portion exhibits a sutural stria on each, and the sculpture near the 

 apex is substriate. 



Length, If lines ; breadth, line. 



Boatman's, Westland. Mr. A. T. Cavell detected one individual 

 in a small hole in the underside of a boulder, on the side of a hill. 



AdolopUS (Gen., p. 940). 



2344. A. montanus, n.s. Shining, pitchy-black ; the elytral 

 margins, the front of the head, and about half of the thorax, 



