CANAKIAN COLEOPTERA, 77 



long (being a trifle wider relatively in front) than that insect ; its 

 prothorax is less rounded at the sides; its elytra have their paler 

 lines much shorter (or less developed), with their margin concolorous ; 

 and its antenna3 are somewhat longer. I have taken it only in 

 TenerifFe, — namely, in the Barranco Santo (near S'" Cruz) and at 

 Las Mercedes ; and it was also met with by Dr. Crotch in the same 

 island. 



120. Hydroporus xanthopus. 



Hydroporus xanthopus, Steph., 111. Brit. Ent. v. .393 (1882). 

 lituratus, Anhc, Hydrocanth. 589 (1838). 



Habitat in aquis TenerifFse, usque ad 8000' s. m. ascendens. 



The present Hydroporus differs a little from its representatives of 

 more northern latitudes, — being a trifle larger, darker, and more ob- 

 long than the ordinary European H. xanthopus ; but it agrees with 

 it so nearly in aU other respects that I cannot believe that it should 

 be regarded as more than a geographical state of that insect : and 

 such (from the examination, however, of but a single specimen), I 

 may add, was the opinion of Dr. Schaiim. It is rather common in 

 Teneriffe (where it was likewise captured by Dr. Crotch) at inter- 

 mediate and lofty elevations. I have taken it at Las Mercedes, the 

 Agua Garcia, Ycod el Alto, and by a smaU spring on the Cumbre 

 adjoining the Cariadas — upwards of 8000 feet above the sea. 



121. Hydroporus planus. 



Dytiscus planus, Fab., Ent. St/st. 1. 195 (1792). 

 Hydroporus holosericeus, Steph., III. Brit. Ent, ii. 61 (1829). 

 ■ planus, Auhe, Hydrocanth. 583 (1838). 



Habitat in Teneriffae aquis, in rivulo ad Agua Garcia \-ulgaris. 



As in the H. xanthoptis, the Canarian examples of this common 

 European insect are, on the average, a trifle larger, blacker, and 

 more convex, as also rather less pubescent, than the ordinary ones 

 of more northern latitiides ; but there is nothing about them, that I 

 can perceive, to justify the idea that they are specifically distinct 

 from the H. planus. I have taken it abundantly at the Agua Garcia, 

 in Teneriffe ; but have not yet observed it in any of the other islands. 

 It was likewise captured in Teneriffe by Dr. Crotch. 



122. Hydroporus Clarkii. 



Hydroporus Clarkii, Woll, Ami. Nat. Hist. (3rd series) ix. 438 [June] 



(1862). 

 Andalusise, Clark, Journ. of Ent. i. 469 [September] (1862). 



Habitat in aquis Fuerteventurae, vulgaris. 



In its general aspect and colouring, as well as in the minute spine 



