jan. — mar. 1857.] Descriptions of new Ceylon Coleoptera. 185 



round either elytron. The first and second on either side run to- 

 wards the apex but come to a stop (very abrupt in most, but less 

 so in some specimens) before reaching it, the lhird after having 

 been interrupted near its base by the subhumeral cavity runs on 

 but does not reach as far as the former, the 4th does not leave the 

 region of the shoulder, the last on either side is very prominent at 

 the base but soon forms an abrupt declivity and runs on as a low 

 ridge to below the middle. The back of all these costae is obtusely 

 dentated. The interstices are marked with large, shallow, trans- 

 verse impressions. The head of the insect is rather large and even. 

 The mandibles are furnished with an obtuse subapical tooth, the 

 two lower thirds are ciliated. The maxillae have the apex of the outer 

 lobe externally enlarged, rounded off and furnished with three strong 

 teeth replaced by cilia on the inside, the inner lobe is conic and 

 similarly provided with teeth and cilia, however, much thinner and 

 finer. The maxill. palpi are robust, the last joint is inflated at the 

 base. The antennal club is hairy, dark (whilst the remaining joints 

 are yellowish), conic and somewhat securiform, the 6th joint being 

 inserted on one side of the 7th. The legs are robusf, the tibiae 

 slightly curved, obliquely truncated at the end, furnished with 

 spines along the outside and with distant cilia along the inner. 



27. Bydrochus lacustris. N. 



H. elongatus, subdepressus, supra metallicus, iridescens, subtus 

 piceus, pedibus, antennis, palpis elytrorumque marginemagis mi- 

 nusve brunneis, mento cyaneo. Long. corp. m. 1 lin., f. multo 

 major atque robustior. 



Palpi maxill. robusti, art. ultimo elliptico leviter inflato. Mandi- 

 bulae apice bifldee. Antennarum clava dense pilosa. Thorax ob- 

 longe quadratus basin versus angustatus basi medio productus, cum 

 capite profunde punctata. Elytra ad humeros oblique truncata, 

 apicem versus sat fortiter angustata, profunde striatopunctata. Tibiae 

 extus spinulosae. 



Specimina nonnulla in lacu Colomb. legi. 



The head is robust, broader than the thorax, the eyes large and 

 prominent. 



