DESCRIPTIONS OF GENERA AND SPECIES 185 



posteriorly. Integurriental glolules colourless and bright-green. OesopJiageal segments 



without nephridia. Intestine surrounded hy a paired blood-sinus. Localities — Germany, 



Ireland. 



This beautiful little Aeolosoma was first referred to by Vejdovsky, in his illustrated 



memoir (24), as probably identical with Leydig's A. niveum (p. 113, footnote), but 



afterwards (18) regarded as a new species and fully described with illustrations. Some 



examples sent from Cork by Prof. Hartog have allowed me to verify the chief points 



in Vejdovsky's paper. It may be the same as a species mentioned by Zachaeias (1). 



(4) Aeolosoma aurigena, Eichwald. 

 Nais aurigena, EiCHWALD, Bull. Soc. Nat. Mosc. 1 847, p. 359. 

 Definition. Two lines in length. Head broader than following segments. Integumental 

 globules golden-yellow, lying close together in regular longitudinal lines. Three or four 

 setae in each bundle. Locality — Russia. 

 Whether this species is really distinct from A. tenebrarum is uncertain. Vejdovsky 

 considers that it is chiefly on account of the regular distribution of the integumental 

 globules. Eichwald's description is unfortunately defective in many important 

 particulars which require to be known before the species can be properly defined. 

 He describes and figures the dorsal vessel as running along the whole length of the 

 body ; but probably the ventral vessel was mistaken for the dorsal. It apparently 

 (so Vaillant thinks) inhabits the Baltic ; this may be an additional argument for 

 its specific distinctness from A. tenebrarum, which has been hitherto only obtained 

 from quite fr,esh water. 



(5) Aeolosoma tenebrarum, Vejdovsky. 

 Aeolosoma tenebrarum, Vejdovsky, SB. Bohm.. Ges. 1879, p. 505 (footnote). 

 Definition. Of considerable size (5-X0 mm.). Head broader than following segments, and pointed 

 anteriorly. Setae capilliform and sigmoid ; supraoesphageal ganglion plainly double, with 

 well-developed lateral lobes. Integumental globules pale-yellow to olive-green. Oesophageal 

 segments with nephridia. Intestine with vascular network. Locality— Water from deep 

 springs in Prague, England. 

 This species is one of the largest of the genus. It has been fully described by 

 Vejdovsky in two memoirs (17 and 24), and some details have been added by myself 

 (74). Its structure is more complicated than that of any other species, and has already 

 been for the most part described in the account of the generic characters of Aeolosoma 

 <viven above. It is the only species except A. leidyi (if this is really distinct) and 



Bb 



