of the Fishery Board for Scotland. 239 



of the flood tide, there is a large admixture of fresh water in this portion 

 of estuary of the Forth. It may be that the peculiar alternating conditions 

 thus produced are favourable to the welfare of this and other organisms ; 

 but whether that be so or not, it is certain that Ptermopsyllus is compara- 

 tively frequent here, while it is apparently exceedingly rare where the more 

 normal marine conditions prevail.* 



Family Harpacttcidje, Claus (in Part). 



Genus Stenhelia, Boeck (1864). 



Stenhelia hispida, Brady. 



1880. Stenhelia hispida, Brady (8), vfol ii. p. 32, pi. xlii. figs. 



1-14. 

 1893. Stenhelia hispida, I. C. Thompson (33), p. 19. 



HaHtat. — Of St Monans. Rather scarce. 



This, which appears to be a comparatively rare species in the British 

 seas, is apparently widely distributed. It has been obtained at Tobermory 

 (Rev. A. M. Norman) ; off Hartlepool and Marsden, Durham, and at 

 Portincross, Ayrshire (Dr G. S. Brady) ; in Ventry Bay, Ireland (Mr 

 E. C. Davidson) ; in rock-pools at Hilbre and Puffin Islands, at Garth 

 Ferry, and in Port Erin Bay, Isle of Man (I. C. Thompson). 



Stenhelia hirsuta, I. C. Thompson. 



1893. Stenhelia hirsuta, I. C. Thompson (33), p. 20, pi. xxxi. 



1894. Stenhelia hirsuta, T. and A. Scott (31), p. 146. 



Habitat. — Off St Monans and at the north end of Inchkeith Island. 



Mr I. C. Thompson, of Liverpool, obtained this interesting species amongst 

 mud dredged from 29 fathoms in the Irish Sea, and about twelve miles west 

 from Port Erin, Isle of Man. The females of this species carry two 

 ovisacs as shown by Thompson's figure ; and several of the specimens 

 obtained in the Firth of Forth were also provided with two ovisacs. 



Stenhelia dispar, T. and A. Scott. 



1894. Stenhelia dispar, T. and A. Scott (31), p. 141, pi. viii. figs. 

 8-12. 



Description. — Female. Length, '55 mm. (/^th of an inch). Rostrum 

 of moderate length. Anterior antenna? short, moderately stout, and eight- 

 jointed, the fifth, sixth, and seventh joints are small, but the last is about 

 equal to the combined length of the two preceding joints, as shown by the 

 annexed formula : — 



2 7 ' 19 • 13 • 14 • 6 • 9 • 8 ■ 18- 

 1 -2-3 -4 ■ 5 • 6 • 7 ' 8" 



The posterior antennae are somewhat similar to those of Stenhelia ima, 

 Brady, except that the last joint of the secondary branch bears one mar- 

 ginal and one apical seta instead of two apical setae. Mouth organs 

 similar to those of Stenhelia ima. First pair of thoracic feet slender, and 

 also somewhat like those of that species. A spiniform plumose seta springs 

 from the lower margin of the second basal joint, and close to the proxi- 

 mal end, interiorly, of the inner branches ; there are no setae on the inner 

 margin of the outer branches. The fourth pair are also somewhat 

 similar to those of Stenhelia ima. The basal joint of the fifth pair is large 

 and sub-triangular, and furnished with three setaj on the inner margin and 



* My son obtained Pterinopsyllus in material from the Moray Firth dredged from 

 a depth of 40 fathoms. 



