856 On Aquatic Carnivorous Coleoptera or Dytiscidce. 



joint of the tarsus. The front and middle tarsi have their third joint short and 

 broad not bilobed, but with the outer portion of its upper surface excavate 

 or channelled for the reception of the base of the terminal joint : this latter is very 

 elongate, two or three times as long as the third joint. The epipleura has at 

 the shoulder a well marked genicular fossa, limited behind by a distinct raised line. 

 This, like the allies, is an inhabitant of South Africa. 



I. 27.— Genus PRIMOSPES. {Vide p. 372.) 



This is at present an autogenus. The insect has much the size of a large 

 Hydropoius and is similar thereto in form. The surface above and below is densely 

 and finely punctate, and the sculpture on the anterior parts of the upper surface 

 becomes obsolete. The head is rather truncate in front. The epipleura; of the elytra 

 possess at the shoulder an indefinite genicular fossa not limited behind by a definite 

 raised line : the swimming legs are quite slender. In other respects the characters 

 are those of Hydropeplus. 



This species is from Capetown. 



I. 28.— Genus CCELHYDRVS. {Vide p. 373.) 



This is again as yet an autogenus : it consists of a species whose individuals have 

 about the size of the Coelambi, and are of short peculiar form, suggesting themselves 

 as an intermediate between the Coelambi and Hyphydri. The head is subtruncate 

 in the middle in front, and not in the least margined ; the prosternal process is 

 rather short and very acuminate, its apex is decurved, and in repose just rests on 

 the extremity of the very short and slender inter-coxal process of the metasternum; 

 this is a little curved towards the mesosternal fork, which, however, it does not 

 attain, and it is obscurely grooved in front. The hind coxae are very large, and their 

 cavities are rather broadly separated, and quite exposed, the coxal processes being 

 adpressed, and without any trace of external acute angle. The swimming legs are 

 rather short, and are moderately stout, the upper third of their tibia;, being a 

 good deal more slender than the apical portion, the spurs are not straight but 

 distinctly slightly crooked or sinuate. The front and middle tarsi have the third 

 Joint rather small ; the terminal joint is likewise not greatly developed, it is however 

 exsertcd, and as long as the third joint. The epipleura has a definite genicular fossa 

 at the shoulder. 



This insect is likewise an inhabitant of Southern Africa. 



