Gaiiy Marine Laboraton/, St. Audreios. 123 



if anything, is more slender. The paragnathi generally are 

 finer than in N. peUiijica, and I. is absent in the present 

 examples and in those proenred by the ' Valoious ' in Green- 

 land, and at most is represented by a single horny point, as 

 in IMarenzeller's specimens. The groups in II. are some- 

 M'hat smaller individually, and apparently less numerous than 

 in N. pelagica. 111. forms a longer transverse band of more 

 minute denticles, and group IV. is composed o£ more acute 

 paragnathi in a double curve, the inner formed of smaller 

 denticles. V. is absent, as in N. pelagica, and VI. forms a 

 group of smaller denticles than in N. pelayica on the eleva- 

 tions at each side. This group is very variable in N. pela- 

 gica, occasionally only a single large denticle being present 

 on each side, and in all cases the paragnathi are larger. 

 YII. and VIII. form the basal row in extrusion, and no 

 groups differ from the homologous parts in A^ pelayica more 

 than these. VII. shows the two largest paragnathi in the 

 series constituting a basal band in extrusion, and which 

 (band) differs from that of iV. pelagica in the isolation of the 

 larger distal and the minuteness of the proximal denticles. 

 In N. pelagica the large distal paragnathi are much more 

 numerous and less regularly arranged, and the proximal 

 smaller denticles are likewise in greater numbers. Side by 

 side the contrast between the two is noteworthy. 



In glancing along the feet of the two forms the rounded 

 and blunt condition of the tips of the processes in N. pela- 

 gica distinguish it, for in N. zonata the lobes are much more 

 acute, and Malmgren^s figures originally indicated this clearly. 

 The examples were procured in Lanibay Deep, Irish Sea, 

 and I have to thank Mr. Southern for the opportunity of 

 examining them. 



Nereis zonata, Malmgren, var. persica, Fauvel, occurs in 

 the Persian Gulf, and has lately been carefully described by 

 Prof. Fauvel^ both in the ordinary and epitokous conditions. 

 The author also states that he considers Nereis procera of 

 Ehlers to be the same species, and so with Nereis pulsatoria 

 of Grube. He concludes that Heteronereis grandijolia $ , 

 INlalmgren [Heteronereis assitnilis, Rathke), is the epitokous 

 condition of Nereis zonata, N zonata appears to have a 

 very wide distribution both ofi" the Atlantic and Pacific 

 shores. 



The epitokous forms of Nereis pelagica are distinguished 

 from those of N. zonata by the coloration, the latter having 



* Arcbiv. Zool. Exper. vol. xlvi. p. 382, pis. xix. & xx, (April 1911). 



