British Freshwater Harpactids, 101 



longer tlian the short outer branches, and composed of two 

 suhequal joints ; inner branches of the second, third, and 

 fourth pairs two-jointed, j^j's^^oi/i^ small. 



Attheyella pygmaa (G. 0. Sars). 



1863. Canfliocamptus pyqmceus, G. O. Sars, " Overs, indenl. Ferskv.- 

 Copep.," Videusk.-Selsk. i Christlania Forhaadl. 1862 (Aftr.), p. 21. 



1880. Attheyella crijptorum, Brady, op, cit. vol. ii. p. 60, pi. lii. 

 fij?s. 1-18. 



1893. Attheyella cryptorum, T. Scott, Eleventh Eep. Fishery Board 

 for Scotland, pt. iii. p. 225, pi. vi. tigs. 21-31. 



This small species appears to be generally distributed and 

 of frequent occurrence in the inland waters of the British 

 Islands. It may be distinguished from the closely allied 

 species Attheyella Zschokhei (Schmeil) by the long curved 

 terminal setse of the outer branches of the fourth pair of 

 thoracic feet and by the depressed opercular plates. 



Attheyella Zschohkei (Schmeil). 



1893. Canthocamptus Zschokkei, Schmeil, Copep. des Rhiitikon-Ge- 



birges, pp. 31-36, Taf. iii. 

 1893. Attheyella propinqua, T. Scott, Eleventh Rep. Fishery Board 



for Scotland, pt. iii. p. 227, pi. vii. figs. 1-11. 



This species, which may readily be mistaken for the one 

 previously described, appears to have an- equally extensive 

 distribution, but it is not so frequently met w^ith. There are, 

 however, comparatively few of the Scottish lochs which I 

 have examined where it has been entirely absent. Mr. D. J. 

 Scourfield has taken A. Zschohkei near London. In this 

 species the terminal setse of the outer branches of the fourth 

 feet have not the long, slender, curved ends so characteristic 

 of A. pygmcea, but the opercular plate is more prominent. 

 Dissection shows, of course, other points of difference, but the 

 differences just referred to may be seen without dissection 

 and with the aid of a hand-lens. 



Attheyella Duthiei^ T. & A. Scott. 



1895. Attheyella Duthiei, T. & A. Scott, Ann. & Mag. Nat. Hist. (6) 

 vol. xviii. p. 4, pi. ii. figs. 1-13 ; also Fourteenth Rep. Fishery 

 Board for Scotland, pt. iii. p. 241, pi. ix, figs. 1-11. 



1902. Canthocamptus Duthiei, Lilljeborg, " Syuop. Spec, hucusqiie in 

 aquis dulcibus Sueciee observ. Fam. Harpactic," K. Sv. Vet.-Akad. 

 Handlingar, Bd. xxxvi. no. 1, p. 41, pi. iii. figs. 5-10. 



Though the distribution of this species appears to be ex- 

 tensivCj it has not been very frequently met with. It was 



