4 «6 GLYCERA ALBA. 



The Nereis alba, Bruguiere, in the ' Encyclop. Methodique ' (1827), in so far as the 

 structure of the foot is given, approaches the southern variety of this species. 



The Glycera Rouxii of Audouin and Milne Edwards (1834) agrees with this form very 

 closely, though some are doubtful on this head. 



Leidy's Glycera americana 1 would appear to resemble this species in essential points. 



The Glycera gigantea of De Quatrefages 2 is apparently this or a closely allied form. 



In all probability the Glycera mitts 3 and G. clubia of Dr. Johnston pertain to this 

 species, and the same may be said of Glycera nigripes, a variety. 



Grube 4 distinguishes G. Bouxii, And. & Edw., from this species by the fact that both 

 hind lobes are long, yet a little shorter than the anterior. All the lobes are thus some- 

 what long, pointed or a little rounded. Ventral cirrus somewhat pointed, about as long as 

 the hind lobe. Papillas of proboscis digit-like, blunt. 



Roule (1896) describes a Glycera convoluta, Keferstein, from the ' Caudan,' but there 

 is nothing to indicate its special differentiation. 



De St. Joseph, while entering Glycera tesselata, Grube, from St. Marguerite, also 

 states that he found Glycera tridactyla, Schmarda, at St. Raphael, a species which 

 Marenzeller (and apparently he also) identifies with Keferstein's Glycera convoluta — here 

 regarded as a synonym of the British form. 



Eisig 5 considered that this species exhibited mastigo-helicoidal locomotion, and 

 cryptoid when boring in sand. Those deprived of the head did not survive. 



Group II. 

 With branchiae. 



4. G-lycera alba, De Blainville, 1828. Plate LXV, fig. 1 — proboscis; Plate LXXVI, figs. 

 3-3 c — feet; Plate LXXXV, figs. 5 and ha — bristles. 



Specific Characters. — Head acutely tapered, with eight segments and four short 

 tentacles at the tip. Body of considerable length (6 to 8 ins.), the segments (100, Ehlers) 

 two-ringed, rounded dorsally and somewhat flattened ventrally, each surface with a 

 median line. The proboscis is short and clavate, and its papillae are small and clavate. 

 It is marked by longitudinal bands, and is transversely wrinkled distally in extrusion. 

 The dorsal cirrus is short with a constriction at the base. The foot is somewhat short 

 anteriorly, longer posteriorly, and in front soon presents two spines and a branchial 

 process, the wall of which differs in structure from the lobes. The branchiae occur on all 

 the feet, except the first and last (about twelve in each case), and arise from the dorsal 

 edge of the foot near the tip. In front of the foot are two flattened lanceolate lobes, and 



i c Fauna Rhode Isl. and N. Jersey/ p. 147, pi. xi, figs. 49 and 50, 1855. See also Yerrill for 

 same form (his Bhynchobolus americanus). 

 ^ <Annel./ii,p. 183, 1865. 



3 ' Cat. Worms Brit. Mus./ p. 185. 



4 < Jahresber. Schles. Gesellsch./ 15th December, 1889, p. 56 (1870). 



5 ' Fauna u. Fl. Neap./ xxviii, p. 263, 1906. 



