56 MOLLU8C.4. 



The most common species, Turbo delphi-nun, L. ; List., 608, 

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

 which have caused it to be compared to a dried fish*. 



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 SCISSURELUE of M. d'Orbigny are living species of the same. 



TURRITELLA, Lam. 



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

 completed, also, by the penultimate whorl; but the shell is thin, and 

 is so far from being convoluted in one plane, that its spire is pro- 

 longed into an obelisk (turreted). The eyes of the animal are 

 placed on the external base of its tentacula ; the foot is smallf. 



They are found in great numbers among fossils ; the PROTO, Defr., 

 should be approximated to them. 



SCALARIA, Lam. 



Have the spire, as in Turritella, elongated into a point, and the 

 aperture, as in Delphinula, completely formed by the last whorl ; it 

 is moreover surrounded by a ridge, which is formed, from space to 

 space, as the shell of the animal increases in size, resembling so 

 many steps. The tentacula and penis of the animal are long and 

 slender. 



One species celebrated for the high price it commands (a), the 

 Turbo sea/am, L. ; Chemn., IV, clii, 1426, &c. vulg. Scalata, 

 is distinguished by the whorls only coming in contact at the 

 points where the ribs unite them, the intervals being open. 



A second species, the Turbo clathrus, L.; List., 588, 50, 51, 

 is not marked by this peculiarity ; it is more slender, and very 

 common in the Mediterranean. 



Some terrestrial or fresh water subgenera, in which the aperture 

 is entire, round, or nearly so, and operculatcd, may be placed here. 

 Of this number is the 



* Add, Turbo nodulosus, Chemn., V, clxxiv, 1723 24; T. nn-inutus, Born., 

 XIII, 3 4 ; Aryonaula, cornu, Fichtcl and Moll., Test. Micros., I, a, e, or LIP- 

 PISTE, Montf. 



f Turbo ;,Hli,'ir,itf. Martini, IV, clii, 1422; T. replicafns, Ib., cli, 1412; List., 

 590, 55 ; T. ucutaiiyulus, List., 591, 59 ; T. duplicatus, Martini, IV, cli, 1414 : 

 T. eroletvs, List., 591, 58; T. (erebru, Id., 590, 54; T. rariegatus, Martini, IV, 

 clii, 1423 ; T. obsolctus, Born., XIII, 7. 



(J3= (a) Tbis is tbe Wentletrap of tbe collectors. We remember seeing one in 

 Bullock's Museum, whicb was valued at 200 guineas, and also four specimens were 

 sold at one sale, whicb brought from 16 to 20. ENO. ED. 



