MOIXUSCA. 95 



lowing remarks concerning the multiloeular testacea have 

 been extracted. The multiloeular testacea may be divided 

 into three sections ; the first including those which are ob- 

 viously spiral ; the second, those which are produced ; and 

 the third, those which are of a globular or lenticular form. 

 These sections are merely provisional, and are only intend- 

 ed to render more obvious and intelligible our notices of 

 the genera. 



1 . The spiral multiloeular testacea. At the head of this 

 first division stands the modern genus NAUTILUS, in which 

 the turns of the spire are contiguous, and the last whorl in- 

 closes the others. The partitions are perforated by a tube. 

 We possess on our shores several species of this genus, of 

 which the N. crispus is the most common. 



In form, the genus LENTICULINA is nearly related to the 

 former. The margin of the mouth reaches to the centre 

 of the shell on both sides, and the partitions are destitute 

 of a syphon. Lamark is in possession of a recent shell of 

 this species from the sea near Teneriff. 



The shells which Mr. Sowerby, in his Mineral Concho- 

 logy, has figured under the genus ELLIPSOLITHES, have the 

 whorls conspicuous, although the mouth clasps the body 

 whorl. But it is easily distinguished from the other genera 

 with which it is related by its elliptical form. 



The genus DISCORBIS of Lamark (formerly called by him 

 Planulites) bears a considerable resemblance to the nauti- 

 lus in form, but the whorls are all apparent, and the parti- 

 tions entire. 



In the genus ROTALIA, the spires approach to a conical 

 shape, and the marginated trigonal aperture is reflected to- 

 wards the base of the shell. It consists of shells which are 

 now found in a fossil state* 



