32 ANNALS OF SCOTTISH NATURAL HISTORY 



Posterior antennae and mouth organs similar to those of 

 Leptopsyllus robertsoni. The first pair of swimming feet are also 

 similar in structure to those of that species, but smaller, and 

 the outer branches are considerably shorter in proportion to 

 the inner branches (Fig. 17). Inner branches of the second 

 and third pairs one-jointed and very rudimentary (Fig. 1 8). 

 Fourth pair similar in structure to those of Leptopsyllus robert- 

 soni, but considerably smaller. The fifth pair are also similar 

 in structure to those of that species, but the coalescent basal 

 joints are proportionally longer, being in length equal to 

 about three-fourths of their entire width at the broadest part. 

 They also differ in form, being subconical in outline and with 

 the apex distinctly bifid. Each of the two apical angles bears 

 two short setse, and the lateral basal lobes are each furnished 

 with a moderately long hair. The secondary joints are very 

 small (Fig. 20). The length of the caudal stylets is scarcely 

 equal to the combined lengths of the last two abdominal 

 segments, while their breadth is nearly equal to half the 

 length. They are each furnished with a few setae, the principal 

 terminal seta being about twice the length of the stylets ; 

 while one of the others, which are very small, springs from 

 near the middle of the outer margin (Fig. 22). The ovisac 

 contains a few very large ova. 



Male. The male is very similar to the female, but the 

 anterior antennae are modified for grasping, and resemble 

 those of the male of Leptopsyllus robertsoni. The fifth pair 

 of thoracic feet, which are very small, also resemble those of 

 that species ; but the coalesced basal joints are shorter, and 

 scarcely extend beyond the base of the secondary joints, 

 while the secondary joints are proportionally larger. In the 

 sixth pair of appendages the inner margins are sinuated and 

 slope considerably outwards, the outer margins are short and 

 nearly straight, and the broadly rounded apex is furnished 

 with two small setae on the outer aspect and a small but 

 stout spine interiorly (Fig. 21). 



Habitat. On the shore at Musselburgh, in the same pools 

 with Leptopsylhis robertsoni. 



Remarks. This species is much smaller than the one 

 last described, and is readily distinguished from it by the 

 form of the caudal stylets, which are comparatively shorter 



