dytisctd^. 73 



(107) 8. * Colymbetes tri-seriatus. Three-rowed Colymbetes. 



C. f tri-seriatus J niger ; antennis, pedibusqiie testaceis; prothorace testaceo fascia discoidali nigra; elytris nigricantibus latere 

 externo flavis, transversim confertissime acuductis, punctis longitudinaliter triseriatis. 



Three-rowed Colymbetes, black ; antennae and legs testaceous ; prothorax testaceous with a discoidal black band; elytra 

 dusky, externally yellow, transversely very thickly acuducted, with a triple longitudinal series of punctures. 



Length of the body 7J lines. 



A single specimen taken. I have a specimen also from New England, taken by 

 Professor Peck. 



DESCRIPTION. 



Body elliptical, rather depressed, underneath black, and covered with an infinity of branching or 

 confluent wrinkles, as if scratched by a pin or needle. Head black, anteriorly testaceous, between 

 the eyes is a pair of transverse red spots ; antennas and palpi testaceous, dusky at the tips : prothorax 

 testaceous with an abbreviated, subbilobed, discoidal band ; variously acuducted so as somewhat to 

 resemble net-work: scutellum ferruginous, black at the base, very minutely and confluently punctured: 

 elytra dusky, which colour, for they are really lurid or dirty-yellow, is produced by an infinity of 

 transverse black lines or furrows, but which at the lateral margin lose their blackness ; besides these 

 there are three rows of punctures arranged longitudinally but not regularly, the first adjoining the 

 suture, and the two others being discoidal ; between the outer one and the margin, especially near 

 the apex, are some scattered punctures; the epipleura, and sides of the fore-breast, are yellow: legs 

 testaceous ; thighs and tibia? punctured. 



This species is intermediate betwen C. striatus and C. dolabratus, with the former it agrees in 

 the majority of its characters, particularly in the longitudinal rows of punctures, except that its sutural 

 one is more perfect ; and with the latter in the prothoracic band, and the colour of the legs. The 

 transverse furrows of the elytra are rather deeper than those of the first-mentioned species, and not 

 so deep as those of the last. 



These insects, adding C.Jnscus, may perhaps be regarded as forming a subgenus, whose common 

 character is the peculiar sculpture of the elytra. 



v. Subgenus Hydaticus. Leach. 



(108) 1. * Colymbetes (Hydaticus) rugicollis. Wrinkle-necked C. Hydaticus. 



C. H. (rugicollis) obovatus, subrufus, nigricanti-nebulosus ; prothorace longitudinaliter acuduclus ; elytris flavescentibus, nigrc 

 reticulata. 



"Wrinkle-necked C. Hydaticus, obovate, subrufous, clouded with dusky; prothorax longitudinally acuducted ; elytra yellow- 

 ish, reticulated with black. 



Length of the body 6 lines. 



Taken in Nova Scotia by Dr. Mac Culloch. 



