142 NERINE FOLIOSA. 



two lateral ridges of hypoderm. The segmental organ appears to have a canal sufficiently 

 large to transmit the sexual elements. 



Under the family of the Ariciens Milne Edwards in 1834 placed the genus Aonis, 

 Savigny, as adopted by De Blainville, the sole species being Aonis foliacea = Nerine 

 foliosa. He thought the group approached Nephthys, though differing in various 

 respects. 



It has been remarked by Sars and Claparede (1868) that if Johnston had been 

 fully acquainted with the genus Spio of 0. Fabricius he would have hesitated to make 

 the genus Nerine, for the sole differential character is the presence of lamellse on the 

 feet of the latter, whereas in the former such are represented only by a minute lobe or a 

 papilla. There is much in common between them, and comparatively little against their 

 union. However, Claparede follows Sars in relegating to the genus Spio those in which 

 the membranous lamella is not soldered to the base of the branchia or disappears entirely. 

 On the other hand, under Nerine are grouped those in which the membranous lobe 

 forms a border to the branchia in the anterior segments. 



Claparede further shows that in certain species there is a circle of anal papillse, in 

 others a small sucker is present, as in Polydora, or in some a simple papilla, but such 

 features are of little moment as between Ferine and Spio. 



De St. Joseph (1894) reviews the history of the genus Nerine, Johnston, and lays 

 stress on Malmgren's duplication by reviving the genus Scolelepis (not Scolecolepis, Blain- 

 ville), created for the Lumbricus squamatus of 0. F. Miiller (Nerine vulgaris, Johnston ?). 

 Malmgren joined with this form Nerine cirrata, Sars, and N oxycephaly Sars. The 

 author rightly states that these three species differ in the form of the head and other 

 particulars, the only common bonds being the membranous lamella on the branchia and 

 the circlet of cirri at the anus. He considers that a new arrangement is necessary. 

 This author describes and figures three stages of the common Nerine from the younger 

 of five bristled segments without tentacles to that of seventeen bristled segments with 

 tentacles of same size. These were captured in tow-nets at Dinard, though the adults 

 were not found between tide-marks. 



Mesnil (1896) gives an historical review of the genus which was established by 

 Johnston for two divergent species, the first being Seolecolepis vulgaris, and the second, 

 he says, pertaining to the genus Spio, but the latter is a misapprehension, for the species 

 is the Nerine foliosa of Sars. He points out that (Ersted, after Sars, distinguished Nerine 

 from Spio by the greater or less development of the dorsal lamella, yet Claparede showed 

 that this distinction is artificial, and held that the association of the lamella with the 

 branchias almost to their extremity was more appropriate. Mesnil, on the other hand, 

 preferred to rely on the distribution of the winged hooks and the anal differentiation. 

 He included Malacoceros, De Quatrefages, and Aonis, Audouin and Edwards. 



1. Nerine foliosa, Audouin and Edwards, 1833. Plate XC, fig. 1 ; Plate XCVI, fig. 13 

 —anterior end; Plate XCVII, figs. 1—1 c— feet; Plate Oil, figs. 7— 7 c— bristles 

 and hook. 



Specific Characters.— Re&d forming a somewhat blunt cone, the dorsal ridge termi- 



