358 MOLLUSC A. 





 has two long tentacula, and the eyes placed on pedicles at their ex- 

 ternal base; the sides of the foot are provided with membranous 

 wings, some times simple, at others fringed, and occasionally fur- 

 nished with one or two filaments. It is to some of these that belong 

 those petrous and thick opercula observed in cabinets, which were 

 formerly employed in medicine under the name of Unguis odoralus. 

 Some of them, Meleager, Montf.(l) are nmbilicated, and 

 others, Turbo, Montf.(2), are not. 



Delphinula, Lani. 



The shell thick, as in Turbo, but convoluted in nearly the same 

 plane; the aperture completely formed by the last whorl, and the 

 margin not tumid; the animal similar to that of a Turbo. 



The most common species, Tlwrfto delphinus, L.; List., 608, 

 45, takes its name from the ramous and convoluted spines, 

 which have caused it to be compared to a dried fish(3). 



Pleurotoma, Defr. 



Fossil shells with a round aperture, on the external margin of 

 which is a narrow incision which ascends considerably; it is proba- 

 ble that it corresponded, like that of the Siliquariae, to some cleft 

 in the branchial part of the mantle. 



M. Deshayes already makes upwards of twenty fossil species. 

 The Scissurell^ of M. d'Orbigny are living species of the same. 



Turritella, Lam, 

 The same round aperture as in Turbo properly so called, and 



(1) Turbo pica, L. List., 640, 30; T. argyrosfomiis, Chemn., V, clxxvii, 

 1758 61; T. margaritaceus, lb., 1762; 7T versicolor, List., 576, 29; 7^. mespi- 

 lus, Chemn., V, clxxvi, 1742 43; T. granulatus, lb., 44 46; T. Indus, lb., 

 48, 49; r. diadevia, Id., p. 145; T. cinereus, Born., XII, 25, 26; J", torquatus, 

 Chemn., X, p. 295; T. imdulaius, lb., clxix, 1640 41. 



(2) Turbo petholatus, List., 584, 39; Tl cockhis, lb., 40; T chrysostomus, 

 Chemn., V, clxxviii, 1766; T. rugosus. List., 647, 41; T! marmoratus, Id., 5S7, 

 46; T. sarmaiicus, Chemn., V, clxxix, I777 18, I78I; T. cornutus, lb., 1779 

 80; 7'. olearius. Id., clxxviii, 1771, 72; T. radiatus. Id., clxxx, 178889; 

 T. imperialis, lb., 1790; 7'. coronatus, lb., 179I 93; T'. canaUculutus, Id., 

 clxxxi, 1794; T. setosus, lb., 95 96; T. spinosus, lb., 1797; T. sparverius, 

 Ih., \798;T. Molikianus, lb., 99-1800; 7\ Spengkriunus, lb., 1801 2; r. 

 castanea. Id., clxxxii, 1807, 1814; T- creniilatus, lb., 1811 12; T. smarag- 

 dulus,lh.,\B,lSl6;T. cidaris, Chemn., V, clxxxiv; T. helicinus, Born., XII, 

 2324. 



(3) Add; Ttirbo nodidosus, Chemn., V, clxxiv, 1723 24; T. carinaius. Born., 

 XlII, 3 4; irgonauta, cornu, Fichlel and Moll., Test. Micros., I, a, e, or Lip- 

 piste, Montf. 



