568 Dr. T. Scott on British Copepoda. 



and they all agree in showing the marked difference in 

 structure of the first pair of thoracic feet mentioned above, and 

 I now propose to remove this species to another genus rather 

 than modify that to which it was provisionally ascribed. 

 The following is the name and definition of the genus : — 



Beatricella *, T. Scott, gen. nov. 



Definition of the genus. — Similar to Delavalia, G. S. Brady, 

 in general appearance. Antennules eight-jointed. Outer 

 ramus of the antennte tliree-jointed. Mandibles as in 

 Delavalia, the terminal branch of the mandible-palp being- 

 furnished with a long, curved, and moderately stout seta. 

 Other moutli-appendages as in Delavalia. 



Both branches of tlie first pair of thoracic feet three-jointed ; 

 inner branches longer than the outer ones, first joint longer 

 than or subequal to the second and third joints. The second 

 to the fourth pairs as in Delavalia. Fifth pair foliaceous 

 and somewhat similar to those of the genus mentioned, 



Beatricella mimica, T. Scott. 



1S97. Delavalia mimica, T. Scott, Fifteenth F. B. Report, part iii. 

 p. 150, pi. i. figs. 1-9. 



In this species the first joint of the inner branches of the 

 first pair of thoracic feet are as long as the entire length of 

 the three-jointed outer branches, but the second and third 

 joints are very short, being together scarcely half as long as 

 the first joint. The fifth pair resemble those of Delavalia 

 reflexa, G. S. Brady, but the basal joint bears interiorly a 

 group of three tolerably short and stout spines and a small 

 spiniform seta. The fifth pair in the male are smaller tlian 

 those of the female ; the basal joint is armed interiorly with 

 a single moderately large and broad spine of a somewhat 

 peculiar shape ; it is broad and flattened rather than round, 

 and with tlie sides parallel except near the distal end, where 

 they rapidly converge and form a triangular extremity ; a 

 minute seta springs from each of the lateral angles at the 

 distal end, while the apex is extended to a fine point; the 

 secondaiy joint is small, subovate in form, and bears three 

 spines on the oblique distal end of tlie outer margin, a 

 moderately long seta at the apex, and a smaller one on the 

 inner margin. 



* Named in compliment to Miss Beatrice Sprague, daughter of 

 Dr. T. B. Sprague, Edinburgh, — a successful student of the Scottish 

 freshwater Entomostraca. 



