1920,] E.Ghosh: Anatomy of the Solenidae. 59 



along the ventral margin for a short distance, A fourth aperture 

 and labial grooves present. Siphon of a single piece, compara- 

 tively short, and with a tentacular fringe. Anterior adductor 

 muscle elongated, but not very narrow. Posterior adductor muscle 

 less elongated. Retractor pedis posterior muscle much smaller 

 than the posterior adductor muscle at its insertion. Foot narrow 

 and elongated, sowewhat flattened laterally and swollen and keeled 

 at the anterior extremity. Fibres of the retractor pedis anterior 

 muscle spread on the inner side of the longitudinal muscle. 

 Anterior lip separated from the anterior adductor muscle by a 

 long interval. Gills elongated, heterorhabdic and plicate, the plicae 

 being free from one another ; gills extending into the siphon. 

 Outer lameha of the outer gill attached to the mantle lobe along 

 their dorsal margin. Inner lamella of the inner gill attached to 

 the side of the foot along its dorsal margin, but free behind in the 

 cloacal region. Coecum of the crystalline style short and extend- 

 ing postero-ventrally from the posterior end of the p3doric 

 chamber. Intestine of Ensis sub-type. Digestive gland extending 

 over the anterior adductor muscle. Heart in the middle of the 

 pericardial chamber. Viscero-parietal ganglia beneath the bifurca- 

 tion of the retractor pedis posterior muscle. Two nerves from 

 each cerebo-pleural ganglion. Two circumpallial nerves. 



The structure and general conformation of the animal dis- 

 tinctly show that the members of the present genus have attained 

 the greatest degree of elongation and are greatly removed from the 

 ancestral stock. 



Gen. Ceratisolen, Forbes. 



1847. Pharns, I.each, Ann Mag. Nat. Hist. XX, p. 272. 



1848. Ceratisolen, Forbes and Hanley, A History of British Molhisca 



and their shells, p. 259. 

 1858. Phariis, Leach in Adams, Gen. Recent Molltisca, II, p. 3^3 ; III, 



pi. 92, fig. 3, 3a, 36. 

 1874. Phartis, Leach in Reeve, Conch. Icon., XIX, fig. 1. 

 1887. Pharns, Leach in Fischer, Man, Conch., p. 1108. 



The anatomy of C. legumen h. has been studied by Bloomer 

 (8, pp. 31-40). The following diagnosis has been drawn up from 

 his work : — 



Animal. Bod}'^ moderately elongated (comparatively shorter 

 than that of Solen or Ensis), nearly straight along the anterior 

 and posterior margins. Pedal aperture extending a short distance 

 along both the ventral and dorsal aspects. A chamber above the 

 anterior adductor muscle opening in front and continuous with the 

 pedal aperture. A fourth aperture at the postero- ventral end of 

 the pedal aperture continuous with it and fringed with tentacles. 

 Siphon of two long and narrow separate tubes. Anterior adductor 

 muscle elongated. Posterior adductor muscle placed rather 

 posteriorly and comparatively small. Retractor pedis posterior 

 muscle much smaller than the posterior adductor muscle at its inser- 

 tion ; bifurcated portions long. Foot large, conical or club-shaped, 

 truncate. Fibres of the retractor pedis anterior muscle passing 

 outside the longitudinal muscle. lyabial palps short and wide. 



