20 BRITISH COPEPODA. 



Posterior antennae 2-jointed, with a minute 1- jointed 

 inner branch. Mandible-palp short (fig. 6), consisting 

 of a basal portion and two short 1-jointed branches. 

 Maxilla armed with several curved teeth (fig. 7), and 

 having a small bilobed setose palp. First pair of foot- 

 jaws (fig. 8) divided into several setose segments ; 

 second pair elongated (fig. 9), 3-jointed, forming a 

 grasping hand, which terminates in a curved claw. 

 First four pairs of feet (fig. 10) nearly alike; both 

 branches 3-jointed. Each foot of the fifth pair con- 

 sists of a single broad fringed plate, larger in the 

 female than in the male. Ovisac single. 



1. TACHIDIUS BREVICOENIS (Miiller). PL XXXVII. 



Cyclops brevicornis, Miiller. Zool. Dan. Prodr., 2414 (1776). Ento- 



mostraca. p. 118 (1785). 

 Fabricius. Faun. Groen., 240 (1780). 



Tachidius Lilljeborg. De Crustaceis ex ord. trib., 



p. 196, tab. xxii, figs. 12 16 ; tab. xxiii, 



figs. 1, 2, 9 ; and tab. xxiv, figs. 17, 18 (1853). 



Brady. Nat. Hist.Trans. Northumberland and 



Durham, v. iii, p. 130, pi. v, figs. 19 (18681). 



Boeck. Oversigt Norg. Copepoder,p.33 (1864). 



Body robust, produced into a short, blunt rostrum ; 

 body-segments fringed on their posterior margins with 

 rows of minute teeth ; last three abdominal segments 

 about equal in length, those of the tail (fig. 1 6) rather 

 longer than broad. Anterior antennae of the female (fig. 

 4) 7-jointed ; first two joints large, third, fourth, and 

 fifth short and nearly equal, sixth nearly as long as the 

 two preceding, seventh very small, the whole limb beset 



