99 j 



2. P. plumula. Berthella porosa, Blainv. t. 16/. f. 4. i 



i5. P. perforatus, Philippi, t. 171. f. 4. 



4. P. aurantiacus, Risso, t. 167- f- 9, t. 167. f. 5 ; Cantraine, t. 174. 



f. 1; Philippi, t. 167. f. 3. 



5. P. De Haaiiii, Cantraine, t. 167. f. 2. 



6. P. brevifrons, Philippi, t. 171. f. 3. 



7. P. . t. 169. f. 1. 



8. P. patagonicus, D'Orb.t. 171. f. 1- 

 .0. P. cornutus, Quoy, t. 174. f. 2. 



10. P. punctatus {Quay, Voy. Ast. t. 22. f. 15, 19). 



11. P. tuberculatus, Meckel. 



12. P. stellatus, Risso. 



13. P. ocellatus, Chiaje. 



14. P. . Ruppell, t. 3. f. 2; t. 16G. f. 1. Lepus marinus, 



Forskael, t. 169. f. 5. 



15. P. Blainvillii, L^S50«, t. 172. f. 1. ^ 1 <? ^ ^^^/ A^l/^ 



16. P.mammillatus, Q«oy,t.l74.f.4. A^^^A^-^^'^V ^ti^ ■ /^^^ "i^j^ 



** Shell very small. 



17. P. testiulinarius, Philippi {Moll. Sicil.) t. 20, 21. f. 1. 1 



18. P. mammillatus, Philippi, not Qnoy. \ 



19. P. Forskalii, C/nV/je, t. 169. f. 4. " J 



20. P. tuberculatus, Chiaje, t. 172. f. 2. I 



21. P. reticulatus. Rang, t. 169. f. 3. 



*** Shell narrow, shelly ? 



22. P. oblongus, Savigny, t. 170, 173. f. 1. 



4. OscANius, n. 325*. Mantle expanded, irregular. 



1. O. membranaceus. Lamellaria m., Montague, t. 103. f. 12. 



2. O. Lesueurii. Pleurobranclms L., Blainv. t. 166. f. 2. 



3. O. luniceps. Pleurobi'anchiis 1., Cuvier, t. 167. f. 2. 



5. Pleurobranch^a, n. 327. 



1. P. Meckeli, Blainv. t. 168. f. 1; Ctwier, 1. 168. f. 3 ; Chiaje, 1. 173. 



f. 2; Cantraine, t. 173. f. 3, from life. Pleurobranchidium della 

 Chaii, Verany, t. 220. f. 3, young. 



2. P. maculata. Pleurobranchidium ui., Quoy {Voy. Astral.) t. 22. 



f. 12. 



i 



6. PoSTEROBRANCHiEA, U. 318. 



1. P. maculata, D'Orb. t. 168. f. 2. 



B. Grill on the inner edge of the front of the side of the mantle. 

 / Foot small. Animal formed for floating. Allied to the Pteno- 



f^ ^ J branchiata, but the gills are not regularly comb-like, but 



qAT^' i tufted, as in this Order. ■, 



l^x/" ' ^ a. Foot compressed, erect, fin-like, with a small flat disk on the ^ j 



>''' « ,yv' hinder edge. Body and shell spiral or subspiral. Teeth, cen- -/r}:^^'^ . ^ 



^^,^^'^ trail, lateral 3'3, elongate, unequal. Heteropodes, IvawA. 



Fam. 8. Pterotracheidce, p. 168. 



Body elongate, transparent. Gill, &c. in a small prominent bag, 

 naked, or covered with a thin subspiral shell. Operculum none. i 



Organs of generation in a common tubercle. j 



H 2 



