On Aquatic Carnivorous Coleoptera or Dytiscidce. 309 



152. Laccophiliis posticus, Aube. M.C. — Ovalis, sat latus et convexus, iiitidus, 

 rufo-testaceus, pi-othoraoe anterius et posterius in medio infuscato, elytris lineirs 

 undulatis, baud interruptis, conflueutibus, nigris; abdoaiine pectoreque nigri- 

 cantibus. Long. 4, lat. 21 m.m. 



This species is closely allied to I,accopbilus complicatus, but is much smaller, 

 and has the black marks on the elytra more confluent, and the breast darker. Tiic 

 male has the front and middle tarsi much inci-assate ; the structure of the last 

 ventral segment so far as I can see in the very imjaerfect examples at my disposal 

 is pretty similar in each sex to what it is in Laccophilus complicatus. 



Madagascar. 575. 



153. Laccophilus irroratus, Aube. M.C. -Ovalis, sat latus, subdepressus, 

 pernitidus, rufo-testaceus, prothorace anterius et posterius longius infuscato, 

 elytris lineis undulatis nigris ; abdomine pectoreque nigricantibus. Long, il, 

 lat. 2i m.m. 



In this species the infuscation of the thorax is extensive so that the marks on the 

 front margin nearly or quite connect. The black marks of the elytra are very 

 waved, and cover it pretty equally, except that at the base they are more or lessi 

 abbreviated, so as to give rise to a more or less distinct appearance of a pale fascia 

 there. In the male the front and middle tarsi are but little incrassate, and the 

 last ventral segment is truncate, bat a little produced in the middle : in the female 

 this segment has the middle part very broad, but it is sinuate on each side, althouy'h 

 the side angles are not produced. 



Mauritius. 570. 



154. Laccophilus medialis, n. sp. — Ovalis, subdepressus, pernitidus, testaceus, 

 elytris in medio fascia lata fusca et ad apicem parcius fusco-irroratis. Lono-. 3r, 

 lat. 2 m.m. 



In this species the dark marks of the elytra are so much abbi-eviated that there 

 is a very broad pale fascia occupying the base, and only very slightly divided at 

 the suture ; the apical jiortion of the elytra is broadly pale, but the dark marks again 

 appear near the extremity in the form of some irregular irrorations. I have seen 

 only the female, in which the sides of the last ventral segment have the appearance 

 of being simply curved, owing to the middle part being very prominent, and sub- 

 compressed laterally. 



Siam, (Bangkok). 577. 



155. Dytiscus variegatus. Germ. Laccophilus variegatus, M.C. — Ovalis, angu?- 

 tulus, minus convexus, nitidus, rufo-testaceus, prothorace anterius et posterius in 



2 S 2 



