124 A ren icolidae 



Arenicola assimilis 



Ashworth, Q. J. Micr. Sci., xlvi (1903), p. 740; Mitt. Zool. Mus. Berlin, iv 

 (1910), p. 351 ; Proc. U.S. Nat. Mus., xxxix (1910), p. 17. 



Arenicola marina oder ein sehr naher Verwandter 



Michaelsen, Eeiseber., in Hamb. Mag. Sammelr., i (1896), p. 9 (Punta 

 Arenas). 



Caudate Arenicola with twenty chaetiferous segments ; thirteen 

 pairs of gills, 1 the first, which is on the eighth segment, may be 

 small or absent ; median lobe of prostomium moderately large, the 

 lateral lobes in the form of a V, the limbs of which are of uniform 

 thickness, that is, not dilated anteriorly though they may be bent ; 

 neuropodia clearly visible in each segment, those of the branchial 

 region are short and do not approach the mid- ventral line ; post- 

 rostral region of the crotchets not dilated (contrast A. pusilla) ; six 

 pairs of nephridia, which open on the fourth 2 to the ninth segments ; 

 several (six to sixteen) pairs of oesophageal glands, the anterior pair 

 long and slender, the others smaller and more or less pear-shaped ; 

 septal pouches absent ; a pair of large statocysts, each with tube to 

 the exterior ; statoliths numerous. 



Arenicola assimilis var. affinis Ashworth. 



Arenicola assimilis var. affinis 



Ashworth, Q. J. Micr. Sci., xlvi (1903), p. 764 (Otago Harb. ; Macquarie I. ; 

 Falkland Is.); Mitt. Zool. Mus. Berlin, iv (1910), p. 351 (Susanna 

 Cove ; Kerguelen) ; Proc. U.S. Nat. Mus., xxxix (1910), p. 18 

 (Stewart I., N.Z.) ; Ann. S. Afr. Mus., xi (1911), p. 18 (Table Bay ; 

 Liideritzbucht ; Plimmerton, N.Z. ; Tasmania). 



Benham, Subant. Is., New Zeal., Art. xi (1909), p. 246 (Campbell I.). 



Ehlers, Discovery Rep., vi (1912), Polych., p. 25 (Auckland I.). 



Arenicola assimilis 



Ehlers, Zool. Jahrb., Suppl. v (1901), p. 265 (Susanna Cove). 



Arenicola assimilis, partim 



Ehlers, op. cit. (1897), p. 104; Fests. K. Ges. Wiss. Gottingen (1901), 

 p. 178. 



Arenicola claparedii 



Pratt, Mem. Proc. Manchester Lit. Phil. Soc., xlv (1901), 13, p. 12 (post- 

 larva). 



Arenicola claparedi Lev. ? 



Ehlers, Abh. K. Ges. Wiss. Gottingen, Math. Phys. Kl., N. F., v, 4 (1907), 

 p. 21 (Warrington, 3 N.Z.). 



1 All the specimens of A. assiinilis (typical form), and those of the variety 

 affinis from Auckland Island, have bushy gills ; all other examples of the 

 variety have been found to have pinnate gills. 



2 In South African specimens of the var. affinis, fifth to ninth. 



3 ? Wellington. 



