252 Part III. — Twelfth Annual Report 



from near the base of the first joint (fig. 11). The basal part of the 

 mandible-palp bears two spinulose setae at the apex. The primary branch 

 is furnished with one marginal and. three terminal setae, while the second- 

 ary branch consists of a small papilla bearing a single small hair. Pos- 

 terior foot-jaws short, stout, two-jointed, and armed with a moderately long 

 terminal claw. First pair of swimming-feet short, moderately stout ; both 

 branches of nearly equal length ; the inner branches composed of two, 

 the outer of three sub-equal joints (fig. 14). The first pair closely 

 resemble those of Atthei/ella pygmcea (G. 0. Sars). Inner branches of 

 second, third, and fourth pairs small, one-jointed. Those of the fourth 

 pair rudimentary, and bearing a short terminal spine. Outer branches 

 elongate, the third joint being nearly equal to the combined length of 

 the other two (fig. 15). The fifth pair consist each of a single joint (or 

 branch), sub-quadrangular in form, but rather longer than broad, and 

 extends obliquely outwards from its attachment to the fifth thoracic seg 

 nient. A number of long stout plumose setae fringe the oblique exterior 

 margin, while a few plain setae spring from the truncate apex, as shown 

 in the figure (fig. 16). Caudal stylets very short. 

 Habitat. — Oft. Musselburgh. Not common. 



Genus Heteropsyllus* nov. gen. 



Body sub-cylindrical. Anterior antennae shorter than the first body seg- 

 ment, and composed of five joints. Posterior antennae like those of Cletodes, 

 but the secondary branch consists of two joints. Mandible-palp small, with 

 a distinct basal part bearing two small branches. Mouth organs as in 

 Pontopolites. Both branches of the first pair of swimming-feet three- 

 jointed, the inner being rather longer than the outer branches. Inner 

 branches of the second, third, and fourth pairs two-jointed, and consider- 

 ably shorter than the elongate three-jointed outer branches. Fifth pair 

 two-branched. Foliaceous. One ovisac. 



Heteropsyllus curtimudatus, sp. n. (PL VIII. figs. 27-34 ; PI. IX. fig. 1.) 



Desertion. — Female. Length, '5 mm. (-^-th of an inch). Body elon- 

 gate, sub-cylindrical. Forehead produced into a short rostrum (fig. 27, PL 

 VIII.). Anterior antennae stout, shorter than the first cephalo-thoracic seg- 

 ment, and composed of five joints, the fourth being very short. The 

 approximate proportional lengths of the joints are shown by the formula : — 



10 • 9 • 7 ' 3 • 14 • 



2 • 3 • 4 • 5 



The two-jointed secondary branch of the posterior antennae is furnished 

 with four small setae, — one at the end of the first joint, a marginal and 

 two terminal setae on the second joint (fig. 29, PL VIII.). Mandible-palp 

 small, but distinctly two-branched (fig. 30, PL VIII.). Posterior foot-jaws 

 small, and in form somewhat similar to those of the species last described. 

 Both branches of the first pair of swimming-feet composed of three sub- 

 equal joints, the inner rather longer than the outer branches (fig. 32, PL 

 VIII.). Outer branches of the second, third, and fourth pairs elongate and 

 three-jointed, somewhat slender. The third joint of all the outer branches 

 is longer than either the first or second joints. Inner branches shorter than 

 the outer, and two-jointed ; those of the fourth pair scarcely longer than 

 the first joint of the outer branches (fig. 33, PL VIII.). The basal joints 

 of the fifth pair are large, broadly but somewhat obliquely rounded at the 

 distal end, and provided with five terminal setae ranged at more or less 

 equal distances from each other round the apex and lower inner margin. 



* "Erepos, different ; \pvk\os, a flea. 



