VII 



MOLLUSC A SYSTEMATIC REVIEW 



13 



..--5 



Phyllidiidse. Numerous branchial lamellte lie in a groove which encircles the body. 

 No jaws and no radula. Pharynx transformed for sucking. Fam. Doridopsidse. 

 Without jaws or radula ; pharynx adapted for sucking. Branchial rosette round 

 the dorsal anus. Dorididse crypto- 

 branchiatae. The branchial rosette 

 round the dorsal anus can be with- 

 drawn into a cavity. (Bathydoris, 

 Archidoris, Discodoris, Diaulula, Kent- 

 rodoris, Platydoris, Chromodoris, etc.) 

 Dorididse phanerobranchiatse. Bran- 

 chial rosette not retractile. (Gonio- 

 doris, Polyccra, Acanthodoris, Idalia, 

 Ancula, Euplocamus, Triopa, etc.) 



Section 2. Cladohepatica. Diges- 

 tive glands more or less broken up into 

 separate branched canals spreading 

 widely in the body. Variously formed 

 dorsal appendages chiefly connected 

 with respiration. Anus usually to the 

 right. Fam. Aeolidiadse (Aeolidia 

 [Fig. 18], ergkia, Tcrgipes, Galvina, 

 Coryptclla, Rizzolia, Facellina, Flabel- 

 lina, Fiona, Glaucus, Janus, Hero). 

 Fam. Tethymelibidse, without radula 

 (Tcthys, Melibe}. Fams. Lomanotidse, 

 Dotouidse Dendronoticlse, Bornellidse, 

 Scyllaeidse, Phyllirhoidse (Fig. 19 ; 

 marine free -swimming animals with 

 narrow laterally - compressed body, 

 without foot or respiratory append- FlG 20 .-Pleurophyllidia TTneata (from below, 

 ages). Fam. Pleurophyllidiidae. Nil- after Souleyet). 1, Genital apertures ; 2, branchial 

 merous branchial lamellte arranged in leaflets ; 3, anus; 4, pedal gland; 5, mouth; 6, 

 a single row on each side along a tent acle shield ; 7, foot. 



furrow between the dorsal shield and the foot (Fig. 20). Fam. Pleuroleuridse, 

 Tritoniadse (Tritonia, Marionia). 



CLASS III. Scaphopoda. 



The body is symmetrical, and elongated dorso-ventrally. The mantle is a tubular 

 sac with a narrow dorsal and a wider ventral aperture. Posteriorly, the mantle 

 cavity reaches to the apical (dorsal) aperture. The shell forms a high tubular cone, 

 and, like the mantle, has a small apical and a larger ventral aperture. Ctenidia are 

 wanting ; the kidneys are paired. The vascular part of the circulatory system is 

 reduced to a ventricle ; without auricles. The sexes are separate. There are no 

 special ducts for the sexual products, which are ejected through the right 

 kidney. The mouth lies at the end of a barrel-shaped snout, and is surrounded by 

 a circle of leaf-like appendages. At the base of this snout there are numerous 

 filamentous appendages, which can be protruded through the lower aperture of the 

 shell and mantle. The foot is ventrally elongated. A radula is found. Limicolous. 

 Marine. Fam. Dentalium (Fig. 101, p. 113). The foot is relatively short ; it is shaped 

 somewhat like an acorn, with a conical central portion and two lateral lobes. 

 Siphonodentalium. The foot is long and worm-like, but broadens out at the end 

 into a disc edged with papillae . 



