98 A REVISION OF THE BRITISH SPECIES OP 



most of the lakes and tarns of the English Lake District; Talkin 

 Tarn and Tindale Tarn, Cumberland ; Ormesby Broad, Norfolk ; 

 Loch at Rockcliff, Kirkcudbrightshire ; Clearburn Loch, Selkirk- 

 shire ; Phoenix Park Lake, Dublin ; and several Loughs about 

 Roundstone, Connemara (G.S.B)^ 



There can, I think, be no doubt vrhatever that the species 

 described by Sir John Lubbock as Diaptomus Wesfwoodn is 

 identical with D. gracilis, G. 0. Sars. Both names date from 

 1863, but as Sars' paper was "read" in 1862 it seems right to 

 give the preference to his specific name. 



3. Diaptomus bacillifer, Koelbel (PI. XIV., figs. 9-13). 

 1882. Diaptomus gracilis, var. (3, Wierzejski (38b), p. 20, 



pi. III., fig. 5. 

 1884. ,, hacillifer, Koelbel (42a), p. 312, pi. I., 



figs. 1-5. 

 1887. ,, montanus, "Wierzejski (50a), p. 6, [fide De 



Guerne & Richard). 

 1889. „ ,, De Guerne & Richard (62), p. 25, 



pi. lY., figs. 17, 23. 



Body slender, widest in front ; last thoracic segment not pro- 

 duced laterally, its angles rounded and bearing two small spines. 

 First abdominal segment having a similar spine on each side. 

 Anterior antennse reaching about as far backward as the furca. 

 Inner branch of the fifth pair of feet in the female indistinctly 

 two-jointed, about half as long as the first joint of the outer 

 branch ; last joint of the outer branch very small, bearing two 

 apical spines, the outermost of which is about half as long as 

 the inner; spine of the second joint very stout, almost straight, 

 fijiely pectinated towards the apex. "Antepenultimate joint of 

 the right anterior antenna in the male bearing a slender styliform 

 process, which is about equal in length to the following joint. 

 Inner branch of the left fifth foot in the male coalescent with 

 the basal joint, the internal margin of which is produced into a 

 long spine : last joint forcipate. Inner branch of the fifth foot 

 of the right side much exceeding in length the penultimate joint 

 of the outer branch." Length of iha female 1*4 mm. 



l^ot having seen the adult male of this species, I have had to 

 depend for that part of the description on De Guerne and Richard, 



