292 OLIGOCHAETA 



obtained specimens. It may not, therefore, be a native of this country. It measures 

 8mm. in length and consists of 18-21 segments. The most prominent difference from 

 the last species is the absence of specially elongated setae from the dorsal bundles 

 of segment iii. This is shown in an illustration (Zincograph) facing p. 337 of the 

 memoir. The ventral setae of the fourth segment were often larger and stouter than 

 the rest ; it is suggested that these may be genital setae, though no other indications 

 of sexual maturity were met with. The segment in which the single pair of commis- 

 sural vessels lie is not mentioned. The coelomic corpuscles are large and greenish ; 

 sometimes quite black owing to quantity of secreted particles. On account apparently 

 of these the worms look of a chalk-white colour when seen with the naked eye or 

 a lens. 



(3) Pristina breviseta, BOURNE. 

 P. breviseta, BOURNE, loc. cit. p. 353. 



Definition. Dorsal setae of two kinds, capilliform and hastiform, the latter cleft at extremity. 

 Capilliform setae of segments II and III shorter than following. Nephridia commence 

 in IX. Had. Madras. 



This Pristina is larger than the other species, and consists of about forty-six 

 segments. It differs from all the species of the genus except P. lutea, in having 

 bifurcate setae in the dorsal bundles. The shape of these, however, is a little different 

 in the two species. The coelomic corpuscles 'are black and very noticeable.' It has 

 been mentioned above that this genus is characterized by having only one cephalized 

 segment, as in the vast majority of Oligochaeta. This condition, however, appears, 

 so far as the present genus is concerned, to be secondary. Both in this species and 

 in the last BOURNE has found that the newly budded head consists of seven segments. 



. (4) Pristina lutea (O. SCHMIDT). 



Naidium luteum, 0. SCHMIDT, Froriep's Notizen, iii. 1847, p. 322. 

 ? Nais caecilia, MAYER, SB. Niederrh. Ges., 1859, p. 45. 



Definition. Length, 15 mm.; number of segments, 30. Dorsal setae, capillary and hastiform. 

 Hearts in V-VII. Glandular ventricle in VIII. Hob. Elbe. 



I have already indicated (p. 289) the reasons which appear to me to render necessary 

 the inclusion of this species in the genus Pristina. Our knowledge of its structure 

 is chiefly due to VEJDOVSKY (24), who has illustrated his description. 



