416 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



smaller than any of the others. The formula shows the 

 proportional lengths. 



Proportional lengths of the joints -66562225 

 Number of the joints - - - 1 2 3 i 5 (5 7 8 



Antennas, mandibles, maxillae, and foot jaws resembling 

 those of D. stromii. Both branches of the first pair of 

 swimming feet robust and three-jointed. The outer 

 branch scarcely reaches to the end of the first joint of the 

 inner branch, the second joint is shorter than the first, 

 and the third joint is shorter than the second. The second 

 and third joints of the inner branch are very short, and 

 of about equal size. The third joint is furnished at its 

 apex with one short, stout claw and one long flexed seta. 

 There is also a minute seta on the inner apical angle. 

 The second, third and fourth pairs resemble those of 

 D. stromii, but are smaller. The fifth pair of feet are 

 somewhat similar to the fifth pair in Stenhelia irrasa 

 already described. The inner margin of the basal joint 

 is furnished between the middle and the apex with three 

 plumose seta?, and there are two sub- apical setae on the 

 outer margin. The apex is destitute of setae, so that 

 there is a distinct space between the setae on the outer and 

 inner margins. The outer branch is furnished with two 

 setae on the outer, two on the inner margins and one on 

 the apex (fig. 4). Caudal furca very short. 



Remarks. — The characters of the antennules and fifth 

 feet easily distinguish this small species from any of the 

 other described members of the genus. 



Pseudothalestris major (T. & A. Scott). 



1895. Pseudowestwoodia major. T. & A. S. Ann. & Mag. Nat. 

 Hist., Ser. 6, vol. xv., p. 56, pi. vi., figs. 17-20. 



Occurrence, No. 1. 



This small species, which closely resembles Westwoodia 



