128 BRITISH COPEPODA. 



the abdomen and finely aculeate. Length - 2 \rd of an 

 inch (I'l mm.). 



One of the less common British species. I have 

 scarcely ever myself taken it, but am indebted to my 

 friend, Mr. E. C. Davison, of Sunderland, for surface- 

 net gatherings in which it occurred, from Grimsby, 

 Teesmouth and Killybegs. The Rev. A. M. Norman 

 mentions it as found " at Hillswick, Shetland, among 

 weeds;" and I have a single specimen, apparently 

 belonging to the same species, which was dredged 

 amongst the Scilly Islands. It occurs also in gather- 

 ings of Copepoda, made by the Rev. A. M. Norman, 

 between tide-marks at Oban, and in material dredged 

 in a depth of five fathoms at the same place. 



5. THALESTRIS CLAUSII, Norman. PL LXII, figs. 112. 



Thalcstris Clausii, Norman. Brit. Assoc. Report, p. 297 (1868). 

 Paraihalestris Clausii, Brady and Bx>bertson. Ann. and Mag. 

 Nat. Hist., vol. xii, p. 136 (1873). 



Animal robust, stout and heavy in all its parts ; 

 rostrum short and blunt, not as long as first antennal 

 joint; anterior antenna of the female (fig. 2) 9-jointed, 

 gradually tapering to the apex ; third and fourth joints 

 of the male antenna constricted, the fifth swollen and 

 forming the base of the conical distal half of the limb 

 (fig. 3). Secondary branch of the posterior antenna 

 2- join ted. Branches of the mandible-palp (fig. 4) two, 

 one small and bearing a single setas, the other larger 



