MOLLUSCA SYSTEMATIC REVIEW 



13 



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

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

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

 the dorsal anus. Dorididaa crypto- 

 branchiatse. The branchial rosette 

 round the dorsal anus can be with- 

 drawn into a cavity. (Bathydoris. 

 Archidoris, Discodoris, Diaulula, Kent- 

 roduris, Platydaris, Chromodoris, etc.) 

 Dorididae phanerobranchiatse. Bran- 

 chial rosette not retractile. (Gonio- 

 doris, Polycera, Aca nthodoris, Idalia, 

 Aiicula, Euplocamus, Triopa, etc.) 



Section 2. Cladohepatica. Diges- 

 tive glands inore 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 (AcvUdiu 

 [Fig. 18], Bcryhia, Tcrgip:s, Galcuia, 

 Coryptclta, JRizzolia, Faccllina, Flabel- 

 lina, Fiona, Glaacuy, Janus, Nero). 

 Fain. Tethymelibidse, without radula 

 (Tethys, Metibc). Fams. Lomanotidse, 

 Dotonidse, Dendronotidse, Bornellidse, 

 Scyllaeidse, Phyllirhoidse (Fig. 19 ; 

 marine free - swimming animals with 

 narrow laterally - compressed body, 



without foot or respiratory append- 

 ages). Fam. Pleurophyllidiidae. Xu- 

 merous branchial lamella arranged in 

 a single row on each side along a tentacle shield ; 7, foot, 

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

 Tritoniadse (Tritonia, 



2-JI 



FIG. -20. Pleurophyllidia lineata (from below, 

 after Souleyet). 1, Genital apertures ; 2, branchial 

 leaflets ; 3, anus ; 4, pedal gland ; 5, mouth ; 6, 



Fam. Pleuroleuridse, 



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. Cteuidia are 

 wanting ; the kidneys are paired. The vascular part of the circulator}' 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 papilke. 



