384 MOLLUSCA. 



are the eyes. The mouth is a vertical orifice, beneath which is a 

 filament on each side, that has all the appearance of a tentaculum, 

 but belonging in reality to the foot. Thebranchise form but a single 

 range along the left side of the roof of the branchial cavity. The 

 right side is occupied by the rectum and the spermatic canal, which 

 also transmits the ova. There is no penis, the animal fecundating 

 itself. 



The species are numerous, but not very distinct. Linnseus 

 left them among the Serpulce(l). 

 The Vermili^, also left by M. de Lamarck near the Serpulse, are 

 similar to the Vermeti(2). 



Magilus, Montf., 



The Magili have a longitudinally carinated tube, which is at first 

 regularly spiral, and then extends itself in a line more or less straight; 

 although the animal is unknown, it is highly probable that it should 

 be placed near the Vermeti(3). The 



SiLiQUARiA, Brug. 



Resembles Vermetusinthe head, the position of the operculum, and 

 in the tubular and irregular shell; but there is a fissure on the whole 

 length of this shell which follows its contour, and which corresponds 

 to a similar cleft in that part of the mantle which covers the branchial 

 cavity. Along the whole side of this cleft is a branchial comb, com- 

 posed of numerous, loose and tabular-like lamellae. Linnaeus left 

 them with the Serpulae, and till very lately they were considered as 

 belonging to the cliJss of the Annelides(4). 



(1) Serpiila lumhricalis, L., Adans., Senegal, XI, 1, and several new species. 



(2) Serpula triquetra, Gm., Born., Mus., pi. xviii, t. 14. 



(o) Magilus antiquus, Montf., II, pi. 43, and Guettard, Mem., Ill, pi. Ixxi, f. 6. 



(4) Serpula anguina, L.; Serpula muricata. Born., Mas., XVIII, 16. 



N.B. M. de Lamarck considered the Siliquariae and the VermiliK as heig-h- 

 bours of the Serpulae. M. de Blainville has approximated them to the Vermeti; 

 M. Audouin has lately observed and described the animal, and to him dp we owe 

 what is stated above. 



