18-- 249 



3rd, adaptations to modifications of hind coxa) for aquatic locomotion : 

 the comprehension of these modifications and their functional values 

 will facilitate the classification of the members of the group. 



Sepidulum teoooides, n. sp. 



Ashy-red, antonnte and palpi yellow, thoi*ax jDroduccd in the 

 middle over the head, the sides indentate in an irregular manner so as 

 to be ragged ; elytra with suture and margin elevated, and each also 

 with three costse, the middle one interrupted near the base. 



Length, 3 mm. 



Head granulate above, the eyes completely divided by the caiithus. Thorax 

 forming a broad lobe in the middle over the head ; on this lobe are two elevated lines, 

 contiguous near the front, then diverging till behind the middle, when they become 

 abruptly approximate, outside these lines is another irregular elevated one on each 

 Bide ; its upper surface is made rough by elevated granules ; the sides are ragged and 

 indented, but narrowed behind, so that the base is much narrower than the front. The 

 elytra have, between the raised lines, coarse punctures, arranged in rather irregular 

 rows, two rows between each of the middle costse, and four between the outer one and 

 the external margin. Metastcrnum granulated, with a slight depression in the middle 

 at the extremity. Legs rather stout, rough ; tarsi and claws moderately large. 



South America, or possibly Mexico. 



Tliis insect is rather closely allied to >S'. costatum, Lee, from Texas ; 

 besides the differences in the sides of the thorax and the sculpture of 

 the elytra, the only important structural characters I notice to dis- 

 tinguish it therefrom are the completely divided eyes, and the con- 

 siderably larger tarsi and claws. 



SEPinrLUM BTJLLATUM, W. Sp. 



Blackish, posteriorly reddish, on the upper surface with elevated 

 metallic tubercles ; legs stout, reddish, antenna) and palpi yellow. 



Length, 3| mm. 



ITcad with raised granules, the clypeus in front metallic ; eyes large, incom- 

 pletely divided by the canthus. Thorax much narrower than the elytra, a good deal 

 narrowed towards tlie base, the front produced in the middle over the head as a 

 broad lobe, in the middle of this near the front is a small elevated space, giving the 

 appearance of another lobe ; the sides are finely serrate, the surface is covered with 

 granules, and has besides some large elevated pustules, some of whicli are metallic at 

 their summit. Elytra roughened with sharj) well-defined granules, and furnished 

 with four rows of larger bullae or tubercles, which are metallic at their summit, the 

 outer row sub-obsolete. Metastcrnum very short, with a raised, transverse, polished 

 space, occupying its middle. Legs reddish, stout; the tibiae rough, with longitudinal 

 lines ; the hind femora angulate beneath in the middle. 



