On Aquatic Caruivorotis Coleoptera or Dytiscidre. 401 



])allidis plus minusve iufuscatis, sat fortiter fere dense sub-ingequaliter punctatis ; 

 coxis posterioribus punctis densis profundis ; abdominis lateribus ad basin dense 

 confluenter punctatis. Long. 3*, lat. 2 m.m. 



Tiie only individual I have seen is an immature female. It is extremely close 

 to H. medialis, but is more regularly oval in form, and shows some slight distinctions 

 of colour and sculjiture. 



North America, (Lake Superior). 213. 



401. Hydroporus medialis, Lee, M.C. — Ovalis, sine pubescentia, nitidus, abdomine 

 pectoreque nigris, capite, thorace, antennis pedibusque testaceis, elytris pallidis 

 plaga magna vaga fusca, crebre sat fortiter oequaliter punctatis, stria discoidali punc- 

 torum impressa obsoleta; coxis posterioribus punctis magnis et profundis fere densis, 

 abdominis lateribus ad basin fortiter confluenter punctatis. Long. 3b, lat. la m.m. 



The sexual difterences are very slight. The male front tarsi are slightly dilated, 

 and the internal claw is a little thicker than the outer. 



Nortli America, (San Diego, California). 212. 



402. Hydroporus ovoideus, Lee, M.C. — Ovalis, sine pubescentia, nitidus, abdomine 

 pectoreque nigris, supra rufescens ; elytris pallidioribus sutura angustissime nigra, 

 sat crebre et fortiter fere sequaliter punctatis ; corpore subtus nitido, coxis posteri- 

 oribus sat crebre punctatis. Long. 32 lat. 2 m.m. 



I have seen only a single specimen of this species which is closely allied to- 

 Hyphydrus marklini (No. 396), but is a little broader and has the punctuation of the 

 elytra and thorax more sparing : the two may, however, perhaps prove to be one 

 species. 



North America, (Lake Superior). 210. 



403. Hydroporus nubilus, Lee, M.C. — Ovalis, angustulus, elongatus, fere sine 

 pubescentia, sat nitidus, testaceus, pectore abdomineque nigris ; elytris siguaturis 

 coalescentibus plus minusve distinctis fuscis, crebre aequaliter fere subtiliter punc- 

 tatis, coxis posterioribus crebre punctatis. Long. 4g, lat. 22 m.m. 



The male has the front and middle tarsi distinctly dilated, and the internal claw 

 on the front ones thickened. The female is not quite so shining as the male, and 

 has the middle tarsi elongate and much compressed. 



North America, (Massachusetts, PhUadelpliia, Texas, Colorado). 208. 



404. Coelambus infuscatus, n. sp. — Oblongo-ovalis, fere sine pubescentia, testaceus, 

 abdomine pectoreque nigris, elytris signaturis magnis coalescentibus fuscis, dense. 



