586 Transactions of the Society. 



Dissotrocha pectinata sp.n. Plate XVI. fig. :'>. 



Specific characters. — Trunk bearing numerous small spines 

 arranged in comb-like groups. On the central trunk there are 

 two "combs" on each of the dorsal longitudinal ridges — on the 

 anterior margin of the trunk and on the anal and pre-anal segments, 

 the ridges are transversely placed ; 2 or 3 teeth in each " comb " ; 

 no long single spines. 



Closely related to D. spinosa (Bryce) {1), it is distinguished by 

 the following characters : D. spinosa has several stout single spines 

 on the anterior margin of the trunk, here replaced by " combs " of 

 short spines ; it has some pairs of single spines on the central trunk, 

 absent from pectinata — it has only small single spicules on the 

 rump, where pectinata has transverse rows of " combs." 



In size, general form, spurs, etc., D. pectinata resembles the 

 rest of the genus. 



Habitat. — Table Mountain, Cape Town. D. spinosa is itself 

 rare, and is only known in Britain, where it has been found in 

 England, Scotland, and Ireland. The above comparison had to be 

 made with my Scotch examples (4-), as Bryce did not figure the 

 dorsal aspect. 



Bibliography. 



1. Bryce, D.— On the Macrotrachelous Callidinas. Journ. Quekett Micr. 



Club (1892) p. 15. 



2. Ehrfnberg — Mikroge ilogie (Leipzig, 1854). 



3. Kirkman, T.— Rotitera of Natal. Journ. R. Micr. Soc. (1901) p. 229. 



4. Murray, J. — Philodina macrostyla and its Allies. Journ. Quekett Micr. 



Club (1908) p. 207. 



5. „ „ Some African Botifers. Journ. R. Micr. Soc (1908) p. 665. 



6. „ „ Bdelloid Rotitera of South Africa. Annals of the Transvaal 



Museum (1911). 



7. Bousselet, C. P.— Rotifera of South Africa. Journ. R. Micr. Soc. (1907) 



p. 395. 



8. „■ „ Geographical Distribution of the Botifera. Journ. 



Quekett Micr. Club (1909) p. 465. 



9. Thorpe, V. G.— Recorded Localities for Rotifers. Op. cit.. 1893, p. 312. 



