BLOOMER : ANATOMY OF CERTAIN SPECIES OF SOLENIDAE. 8l 



Solen eorneus, Lam. 

 PI. X, fig. 4- 

 \\'hen compared with S. cwjina shows the following differences : — 

 The animal is not so muscular. The ventral part of the mantle lobes at 

 the anterior end projects more anteriorly than the dorsal part (fig. 4, M.L ), 

 whereas, in .S. ra'jina they are not as angular The anterior adductor muscle 

 is proportionately not so wide, the distal portion of the foot is still shorter, 

 and the posterior adductor muscle is much narrower, while the part of the 

 animal postericjr to the posterior adductor muscle is considerably longer. 

 The internal structure apparently is the same. 



Solen gouldi, Conr. 

 PI. X. fig. 5. 



Only one specimen of the above in the collection, which unfortunately 

 had been pressed out of shape, and is in a very bad state of preservation. 



It appears to be very similar to S. rw/ina, only differing from it in the 

 anteiior projection of the ventral portion of the anterior part of the mantle 

 lobes (fig. 5, J/. L.), more so than in »b'. cor/ieiis, Lam. 

 Cultellus javanieus- Lam. 

 PI. X, fig. 6. 



There are two specimens of the above in the collection, but, owing to 

 their imperfect preservation, it is impossible to make out with any degree of 

 certainty a great deal of the internal structure, particularly the alimentary 

 canal. 



The animal is slightly curved outwardly along the dorsal surface, and 

 inwardly along the ventral surface, the centre of the latter being a little 

 compressed. The anterior and posterior parts are tapered, and the ends 

 rounded. 



The mantle lobes are concresced along the whole of their ventral sur- 

 face, so that the pedal aperture is confined altogether to the anterior end, 

 and there is no fourth aperture. The muscles of the pallial edge foim only 

 a shallow itand, and are not strongly developed. At the posterior end is the 

 siphon, which likewise is not very muscular. In its proximal part the ex- 

 halent (fig. 6, AV. aS' ) is separated from the inhalent chamber (fig. 6, In. S.) 

 by a muscular wall, having its anterior side joined to the gills. The 

 free portions of the siphon are very short, and encircled by a tentacular 

 fringe. 



The foot (fig. 6, F.), which at the distal end is axe-shaped, is long and 

 of a nearly uniform depth. 



The inside edges of the bases of the gills are joined together, while the 

 outside edges have become disconnected with the pallial wall, as so 

 frequently happens in the case of S. catjina. 



One of the chief characteristics is the proportionately greater lengtli of 

 the posterior part of the animal. 



