290 OLIGOCHAETA 



The two new species of BOURNE Pnstina equiseta and P. breviseta do away 

 with the first and second differential characters. In view of the identity in the 

 cephalization of the two genera, the remaining points of difference are, perhaps, 

 hardly of sufficient importance to warrant generic separation, particularly as only 

 one species of Naidium is known, and its range of specific variation, therefore, not 

 ascertained. In both Naidium and Pristina the restriction of the pharynx to two 

 segments, and the great development of the septal glands are especially remarked 

 upon by VEJDOVSKY, and constitute a bond of union, which may be considered to 

 counterbalance the differences mentioned above. 



The well-marked species belonging to this genus are only five, viz.: 



(1) Pristina longiseta, EHEENB., Europe and N. America. 



(2) equiseta, BOURNE, England. 



(3) ,, breviseta, BOURNE, Madras. 



(4) lutea, O. SCHM., Europe. 



(5) proboscidea, F. E. B., S. America. 



One or two doubtful forms have also been described too incompletely for satisfactory 

 recognition l . 



Pristina inaequalis of EHBENBEKG has been thus defined by him : 



'Setis quaternis inaequalibus, una longissima, reliquis brevissimis, pan secundo non diverse, 

 unoinis, subquinis subulatis." 



Pristina brericeps (= Naidium breviceps, 0. SCHMIDT) is thought by VEJDOVSKY to be an 

 Enchytraeid. 



Nais temaria of SCHMAKDA is doubtfully transferred by VAILLANT (6, p. 357) to Naidium. The 

 chief reasons for believing it to be a member of the genus Pnstina are the absence of eyes, and 

 the commencement of both dorsal and ventral setae upon the same segment. The dorsal setae 

 are capillary only. The intestine is said to have a spiral arrangement. The worm occurs in 

 Louisiana, Central America, Cuba, and Jamaica. 



(i) Pristina longiseta, EHRENBERG. 



P. longiseta, EHRENBERG, Symb. Phys. 1828. 



Pristinais longiseta, GERVAIS, Bull. Ac. Roy. Belg. 1838, p. 17. 



Mais longiseta, n'UDEKEM, Bull. Ac. Roy. Belg. t. xxii, pt. ii. 1855, p. 552. 



Stylaria longiseta, TAUBER, Ann. Dan. 1879, p. 73. 



Definition. Length, 8 mm. ; number of segments, 20. Dorsal Setae of segment III much 

 longer than the other. Prostomium long. Glandular ventricle in segment VIII. 

 Five vascular arches connecting dorsal and ventral trunks. Nephridia commence in X. 

 Hal. Europe. 



1 It is possible that 'Lmnlrims hirsutvs' of DALYELL (p. 140) is referable to this genus. 



