THE GASTROPODA 



179 



cnidosacs are found in the integuments ; e.g. Pseudovermis paradoxes 

 (Fig. 169). 



FAMILY 1. EOLIDIDAE, d'Orbigny. Dorsal papillae spindle-shaped or 

 club-shaped, each ending in an open sac of endodermic origin which 

 communicates with a hepatic caecum and contains nematocysts. Genera 

 Eolis, Cuvier ; the anterior angles of the foot prominent ; rhinophores 

 smooth ; dorsal papillae compressed ; British { 



(Fig. 160, A). Facelina, Alder and Hancock ; 

 rhinophores foliated; radula 

 triserial ; British. Tergipes, 

 Cuvier ; rhinophores simple ; 

 radula uniserial ; dorsal pa- 

 pillae in a single row on 

 either side ; otocyst with an 

 otolith ; British. Gonieolis, 

 Bergh ; no eyes. Cuthona, 

 Alder and Hancock. EmUe- 

 tonia, Alder and Hancock. 

 Galvina, Alder and Hancock. 

 Calma, Alder and Hancock. 

 Hero, Loven ; a frontal 

 velum ; rhinophores simple ; 

 dorsal appendages in umbel- 

 liform clusters. FAMILY 2. 

 GLAUCIDAE, Gray. The 

 body furnished with three 

 pairs of lateral lobes bearing 

 the tegumentary papillae ; FIG. 165. 



f ree _ Sagittal section of a 

 dorsal papilla of Kol is. c.s, 



forma, cnidocystic sac ; d, duct 



Fio. 160. 



Evaginated cnidocyst 

 from Kol is jnim-tnta, x 500. 

 (After Vayssii-rft.) 



foot very narrow 



swimming pelagic 



Genus -Glow, Forster. JNjjj* 



FAMILY 3. H E D Y L I D A E, cnidocystic sac ; ep, exter- 



Bergh. Body elongated ; 

 the visceral mass marked 

 off from the posterior part of the foot ; dorsal tegumentary append- 

 ages absent or reduced to a single pair ; spicules developed in the 

 integument. Genus Hedyle, Bergh (Fig. 168) ; from the Black Sea, 

 Sea of Marmora, Mytilene, Flores. FAMILY 4. PSEUDOVERMIDAE, 

 Pelseneer. Head devoid of tentacles ; body elongated ; the anus on 

 the right side. Genus Pseudovermis, Periaslavzeff (Fig. 169) ; from 

 the Black Sea and Mytilene. FAMILY 5. PROCTONOTIDAE, Alder and 

 Hancock. Anus situated posteriorly in the median line of the back ; 

 anterior tentacles atrophied ; foot broad. Genera Janus, Verany ; 

 a median crest between the rhinophores ; British. Proctonotus, Alder 

 and Hancock ; no intertantacular crest ; British. FAMILY 6. DOTONIUAE, 

 Adams. Bases of the rhinophores surrounded by a sheath ; dorsal 

 papillae club-shaped and more or less tuberculated, arranged in a single 

 row on either side of the dorsum ; no cnidosacs. Genera Doto, Oken ; 

 a frontal veil ; British. Gellina, Gray ; no frontal veil. Heronwrpha, 



