336 My. a. E. Verrill on new American 



angle. The second and third joints together have a nearly 

 triangular form, the breadth being about half the length ; the 

 outer edge is regularly rounded, shorter than in the preceding; 

 it forms little more than a right angle with the front edge, 

 which is nearly sti-aight or a little concave, sometimes slightly 

 convex at the last articulation, but not forming a distinct angle 

 there ; the inner edge of the hook is a little concave on the 

 first joint, becoming convex at the last articulation, where 

 there is a distinct but very obtuse angle. The last joint is 

 almost regularly triangular, about as broad as long, tapering 

 to an obtuse point, the inner edge being a little convex. The 

 antenna are very slender, and do not reach the first articula- 

 tion of the claspers. The caudal appendages are smaller than 

 in A. gracilis y and scarcely longer than broad, rounded at the 

 end, terminated by nine or ten very slender plumose setffi. 

 The egg-pouch of the female is broad flask-shaped, strongly 

 convex in the middle below, the sides not fonning such sharp 

 angles as in vl. gracilis. 



The English specimens of A. salina, as figured by Baird, 

 differ from both the preceding species in having longer, more 

 curved, and sharper clasping-hooks, and the basal appendage 

 more elongated ; the egg-pouch, though badly figured, is of a 

 very difterent form. The French specimens, as figm-ed by 

 Joly, ap])ear like a distinct species, the egg-pouch being of a 

 very different form, and the caudal appendages very much 

 longer and larger than in either of our species, while Baird's 

 figure represents them as very small 5 but his specimens appear 

 to have been smaller, and may have been immature, for these 

 species begin to breed before they are half groAvn. Whether 

 the French species be distinct from the English can only be 

 determined by additional examinations, especially of the male ; 

 fin- the male of the former appears not to have been figured 

 hitherto. 



Branchipus, Schaffer. 



Branchijma, Schiiffer, Elementa Entoniologica, 1706 (tj'pe, B. pisci- 



formis=(?) B. stagnalis, Linn, sp.)- 

 Branchipus (pars), Lamarck, Latreille, Leach, Edwards. 

 Chirocephalus (pars), Dana (non Benedict Provost, 1803; Jurine, 



Thompson, Baird). 



Under the name of Branchipus at least four generic groups 

 have been confounded by various authors. 



Brancliipxis should be restricted to the original s])ccies de- 

 scribed by (Schiiffer and the allied species, of which B. stagnalis 

 (Lirm. sp.) is one, and if not identical with B. pise ijvr mis, as 

 is generally supposed, must be closely allied to it. 



