MOLLUSCA. 433 



inouth, between that organ and the funnel. The suckers 

 are pedunculated, with their margin strengthened by a 



Syphon is marginal. The Ammonites discus of SOWERBY appears to be of 

 this genus. 



Nearly allied to the preceding is the TURRILITES of MONTFORT. It is si- 

 milar in internal structure, but while the shells of the former are spirally 

 discoid, those of the present genus are spirally turreted, resembling a Turbo 

 or Turricula. Four species are figured by SOWERBY in his Mineral Concha^ 

 logy, Vol. I. 



The genus SCAPHITES, formed by PARKINSON, possesses very peculiar cha- 

 racters. It commences with a depressed volution, the last turn of whichj 

 after being enlarged and elongated, is diminished and reflected inwards. 



2. Multilocular testacea with the shell produced. It must be confessed 

 that the genera of this section are but imperfectly understood. The recent 

 kinds are too small to admit of arty investigation of the animal, so that we 

 are left entirely to conjecture* 



The genus HIPPURITES is of a conical form, and either straight or crook- 

 ed. Within it is transversely chambered, and furnished with two lateral, 

 longitudinal, obtuse, converging ridges. The last chamber is closed by ah 

 operculum. 



In the ORTHOCERA the shell is straight or slightly bent, and conical. The 

 chambers are distinct, and pierced with a tube. We possess on our shores 

 many minute species of this genus. 



The genus BACunxEi of FAUJOS ST FOND, possesses a structure similar 

 to the Ammonites, the inner walls being articulated with sinuous sutures, 

 and the partitions perforated. The shell is fusiform, or bent into two paral- 

 lel limbs* Mr PARKINSON has contributed greatly to our knowledge of this 

 genus, and has termed it Hamites. We prefer the name of the original dis- 

 coverer to that of our English naturalist, which is very faulty : For, ac- 

 cording to PLINY, " Hammites ovis piscium similis est." 



In the fossil genus of Belemnites, the shell is straight and conical, the apex 

 is solid, with a groove or fold on one side, and at the thick end there is a co- 

 nical cavity rilled with a shell divided into chambers, all of which are penetrated 

 by a pipe. If we regard this body as the remains of a cephalopodous ani- 

 mal, we may consider the exterior solid extremity to have been a corneous 

 covering, and the chambered alveolus the seat of the body of the ani- 

 mal, which likewise enveloped the base. That the solid base was 





VOL, II EG 



