336 Mr. 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 straight 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 

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

 tion of the claspers. The caudal appendages are smaller than 

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

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

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

 convex in the middle below, the sides not forming 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 sharjDer clasping-hooks, and the basal appendage 

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

 very different form. The French specimens, as figured by 

 Joly, appear 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 ; but his specimens appear 

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

 species begin to breed before they are half grown. Whether 

 the French species be distinct from the English can only be 

 determined by additional examinations, especially of the male; 

 for the male of the former appears not to have been figured 

 hitherto. 



Branchipus, Schaffer. 



BrancJiipus, SchfiiFer, Elementa Entomologica, 1766 (type, B. pisci- 



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

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

 Chirocephahis (pars), Dana (non Benedict Prevost, 1803; Jurine, 



Thompson, Baird). 



Under the name of Bi'ancMjms at least four generic groups 

 have been confounded by various authors. 



Bra nchipus should be restricted to the original species de- 

 scribcd by ISchafFer and the allied species, of which B. stagnalis 

 (Linn, sp.) is one, and if not identical with B. pisciformis, as 

 is generally supposed, must be closely allied to it. 



