MOLLUSCA. 97 



genus are spirally turreted, resembling a Turbo or Turri- 

 cula. Several species are figured by Sowerby in his Mine- 

 ral Conchology. 



The genus SCAPHITES, formed by Parkinson^ possesses 

 very peculiar characters. It commences with a depressed 

 volution, the last turn of which, 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 any investigation of the animal, so that we are 

 left entirely to conjecture. 



The genus HIPPURITES is of a conical form, and either 

 straight or crooked. Within it is transversely chambered, 

 and furnished with two lateral, longitudinal, obtuse, con- 

 verging ridges. The last chamber is closed by an 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 BACULITES of Faujas St. Fond possesses a 

 structure similar to the ammonites, the inner walls being 

 articulated with sinuous sutures, and the partitions perfor- 

 ated. The shell is fusiform or bent into two parallel limbs. 

 Mr. Parkinson has contributed greatly to our knowledge of 

 this genus, and has termed it Hamites. We prefer the name 

 of the original discoverer to that of our English naturalist, 

 which is very faulty. For, according to Pliny, " Hammites 

 ovis piscium similis est." 



In the BELEMNITES the shell is straight, conical, pointed, 

 solid at the summit, and furnished with a lateral gutter. 

 There is seldom more than one of the cells apparent, of a 



