DESCRIPTIONS OF GENERA AND SPECIES 185 



posteriorly. Integumental globule* colourless and bright-green. Oesophageal segments 

 wit/tout nephridia. Intestine surrounded by 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. HARTOQ have allowed me to verify the chief points 

 in VKJDOVSKY'S paper. It may be the same as a species mentioned by ZACHARIAS (1). 



(4) Aeolosoma aurigena, EICHWALD. 

 Nais aurigena, EICHWALD, Bull. Soc. Nat. Mosc. 1847, p. 359. 



Definition. Two lines in length. Head broader (/tan following segments. Integnmental 

 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 fresh water. 



(5) Aeolosoma tenebrarum, VEJDOVSKY. 



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

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

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

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

 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 Aeolusoma 

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



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