20 BRITISH COPErODA. 



Posterior antennas 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 BREVICORNIS (Miiller). PI. 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. 1216; 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 (1868). 



Boeck. OversigtNorg.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. 16) 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 



