On Aquatic Carnivorous Coleoptera or Dytiscidce. 669 



A variety occurs in which the yellow vitta is indicated only iu its basal and 

 apical j)ortions. 



Madagascar, Jlauritius, Senegal, CafFraria. 1040. 



104-6. Hydaticus rectangulus, n. sp. — Ovalis, sat latus, nitidus, capite anterius 

 testaceo, posterius nigro, thorace in medio nigro, ad latera late testaceo, elytris 

 nigris, vittis duabus latis integvis, interiore a sutura parum distante, testaceis ; 

 corpore subtus piceo, antennis pedibusque anterioribus testaceis, tibiis intermediis 

 pedibusque posterioribus piceis ; elytris punctis seriatis minutis. Long. 12i, lat. 

 li m.m. 



This species is of the form of Dytiscus vittatus (No. 1049), but is readily distin- 

 guished from it by possessing two broad longitudinal bands on the wing-cases ; the 

 inner of the two is separated from the suture only by one-fourth, or less, of the 

 breadth of the wing-cases ; moreover, at the base this yellow vitta has a small 

 internal prolongation so that it nearly touches the scutellum. From Hydaticus 

 bivittatus, the species is distinguished by its broader form, by the broader yellow 

 stripes of the elytra, and by the shorter and thicker swimming legs, the hind mar- 

 gins of the tarsal joints of which are moreover furnished with elongate cilise : also 

 the external yellow band of the elytra, instead of continuing along the outer 

 margin from the base to the apex, diverges from the outer margin a short distance 

 behind the shoulder. A variety occurs in which the yellow bands are so broad as 

 almost to be united into one large patch, the black vitta separating them being 

 correspondingly diminished in size. Of the male I have seen only a single badly 

 preserved individual, it appears not to differ in its tarsi from Dytiscus vittatus ; the 

 female has no sexual sculpture. 



Persia, (Dr. Millingen) ; Northern India, (0. Boyd) ; (Kulu Kangra, Punjaub). 1041. 



1047. Hydaticus duplex, n. sp. — Oblongo-ovalis, sat latus, capite anterius testaceo, 

 posterius nigro, thorace nigro, ad latera testaceo, elytris nigris, vittis duabus integris 

 testaceis, vitta interna, a sutura sat distante, pone basin cum fascia transversa flava 

 fere ad scutellum extensa, coujuncta; corpore subtus nigro-piceo, antennis pedibus- 

 que anterioribus testaceis, tibiis intermediis piceis, pedibus posterioribus fere nigris, 

 elytris punctis seriatis sat conspicuis. Long. 14t, lat. 8 m.m. 



This species seems very closely allied to D. vittatus, but is rather larger than the 

 longest individual of that species and is more oblong in form : the external yellow 

 vitta of the elytra is continued to the extremity of the wing-case, while the internal 

 one is towards the apex approximated a little nearer to the suture than it is in D. 

 vittatus, and moreover sends off near its commencement an internal prolongation 



4 B t 



