NEW BRITISH SPECIES, ETC., IN 1866. 57 



and the deeper punctuation on each side of the base of its 

 thorax (the absohite punctured space being, however, smaller), 

 will readily distinguish it. Mr. Blackburn's insect has dull 

 reddish elytra, with the suture broadly and obscurely darker; 

 being one of the numerous varieties mentioned by Gyllenhal 

 and Thomson. 



2. Ilybius sub^neus, Er., Col. March, i, 156, 6; Kedt., 



Faun. Austr. 95, 5; J. A. Power, Ent. 29, p. 79. 



Dr. Power records the capture, near Peckhara, of a female 

 Ilyhius which he refers to this species, and states to be nearly 

 allied to I. fenestratiis, but darker in colour and more con- 

 tracted and "lumpy" in form. 



Redtenbacher differentiates it from fenest rat us by its being 

 broadest at (instead of behind) the middle, its blacker colour, 

 and the na7'row red margin of its thorax and elytra. 



Dr. Power also notices, in addition to the series of longi- 

 tudinal plicte on the underside of the male in this genus, a 

 character in the last segment of the female. He remarks 

 that in that sex of I. fenestratiis there is a mere triangular 

 notch, with a ridge extending from it ; whereas in the now 

 recorded insect the notch has no distinct ridge connected with 

 it, but has its margins flattened " in the most remarkable 

 manner.'^ 



3. Hydroporus Sanmarkii, Sahib. 



Mr. Crotch ('^The Entomologist," No. 31, p. 110) now 

 ranks this insect as a " sub-species," instead of a variety, of 

 M. rivalis, Gyll., as in the 1st ed. of his Catalogue. He 

 states that varieties of rivalis are often confused with it ; and 

 that he can see no difference except in coloration. 



