282 GEO. n. HORN, M. D. 



Hydroporus laevis Kby., is probably the same as that subsequently 

 described by LeConte as duodecimlineatus and, if so, Kirby's name 

 should prevail. 



Hydroporus picatus Kby., and similis Kby., are forms of the variable 

 impresso-punctatus Schall. 



Laccophilus biguttatus Kby. — This has been placed as a synonym of 

 two other species at various times, but it is probably not a Laccophilus at 

 all and seems rather to be a species of Hydroporus, perhaps allied to 

 pulcher Lee. 



Colymbetes semipunctatus Kby., is an Agabus and known to us. 



Colymbctes biculor Kby. and phaeopterus Kby. — From an examina- 

 tion of the types of these two species in the British Museum, they 

 seemed to be merely color varieties of one species and identical with the 

 form described by Sharp as Agabus coiifinis Gyll. I believe ambiguus 

 Say to be the same species, and the name is older than any of those 

 above quoted. 



Colymbetes reticulatus Kby., seems to be the same as that described 

 by Aube a year or two later as Agabus reticulatus. 



Colymbetes picipes Kby., is Iybius augustior Gyll. 



Colymbetes assimi/is Kby., is Rhantus binotatus Harris. 



Colymbetes triseriatus Kby., is C. sculptilis Harris. 



Colymbetes rugicolfis Kby., is Graphoderes liberus Say. 



Colymbetes Mac Cttllochii Kby., is Acilius mediatus Say. 



Dytiscus Ooligbuliii Kby., is considered to be confluens Say 7 which 

 in turn is dauricus Gebl. 



Dytiscus Harrisii Kby., a well-known species. 



Dytiscus FranMinii Kby., from the description it also must be re- 

 ferred to dauricus Gebl. 



The following species are sufficiently conspicuous to warrant their 

 description in an isolated manner : 



LACCOPHILUS Leach. 

 L. lateralis n. sp. — Oval, rather broad, yellowish testaceous, elytra black 

 with few yellow marks. Head and thorax obsoletely finely punctulate. Sides of 

 thorax feebly arcuate, hind angles rectangular, color yellowish testaceous with a 

 bilobed piceous spot at the apex and a smaller one at base. Elytra very min- 

 utely punctulate, black, with few yellow spots each indicating a tendency toward 

 three transverse series, epipleurae pale. Body beneath nearly smooth, abdomen 

 obliquely scratched. Length .16-.18 inch; 4-4.5 millim. PI. IX, fig. 3. 



This species is closely related to insignis and picfus, more particularly 

 the latter in form, although even a little more broadly oval. The spots 

 on the elytra are much less numerous and the epipleurae pale in their 



