Dr. T. Scott on British Copepoda. 460 



the ( Twelfth Annual Report of the Fishery Board for 

 Scotland/ pt. iii. p. 244, pi. vii. figs. 4-12. 



Remarks. — Pteropsyllus consimilis differs from the more 

 typical forms of Tetragoniceps in the structure of the anterior 

 antennae and more particularly in that of the first and fifth 

 pairs of thoracic feet, and these differences are so obvious that 

 the species ought, I think, to be removed from the genus to 

 which it was at first doubtfully ascribed. The species 

 appears to be moderately rare. I have no record of its 

 occurrence from any place outside the Forth Estuary. 



Genus Evansia, T. Scott, nov. 



In 1892 I described under the name of Tetragoniceps 

 incertus a Copepod which, a short time before, had been 

 observed in the Forth Estuary. In its general form the 

 species was very like Tetragoniceps, but it differed so greatly 

 in tlie structure of some of its appendages that its place in 

 that genus could only be regarded as temporary. 



Further research has shown that the species has a tolerably 

 wide distribution, and the examination of additional specimens 

 proves that its position in Tetragoniceps is untenable. I there- 

 fore propose to remove it to a new genus — Evansia, which is 

 named in compliment to Mr. William Evans, F.R.S.E., 

 Edinburgh, whose successful researches in various branches 

 of natural history have added greatly to our knowledge of the 

 fauna of Scotland. 



The following is a description of the more important 

 characters by which the genus may be distinguished. 



Female. — Body narrow and elongated. Antennules (ante- 

 rior antennse) seven- or eight-jointed and about as long as the 

 cephalothoracic segment. Posterior antennae three-jointed .; 

 outer ramus small or nearly obsolete. Mandibles small, basal 

 part usually dilated, distal part narrow, and with the truncated 

 apex obscurely toothed ; palp elongated and slender, composed 

 of a single biarticulate branch. Other mouth-organs nearly 

 as in Tetragoniceps. First pair of thoracic legs nearly as in 

 Tetragoniceps. In the next three pairs the outer branches 

 are three-jointed, slender and elongated as in those of the 

 genus named, but the inner branches are very small and 

 consist of only one joint. Fifth pair small, uniarticulate, and 

 narrowly triangular in form, and terminate in a stout apical 

 spine. Abdomen composed of four segments. 



Male. — The male is similar to the female, except, 1st, that 

 the antennules are modified and hinged for grasping ; 2nd, 

 that the second pair o£ thoracic feet are provided with an 



