241 



Art. VI. Lamarck's Genera of Shells. 



[Concluded from Vol. XVI. p. T9.] 



4tli Family. 

 Sphxrulata*. (3 genera.) 



Shell globular, spheroidal, or oval ; whorls of the spire envelop- 

 ing, or the chambers united under one covering. 



The sphserulata are small, spheroidal or oval, multilocular shells, 

 some having no other cavity than those of the chambers, and 

 their whorls enveloping one another; others are furnished with 

 a peculiar internal cavity, and are composed of a series of elon- 

 gated, narrow, contiguous chambers, arranged in a portion of a 

 circle, which, by their union, form a single coat, that envelopes the 

 central cavity. 



1. MillioHtesf. 



Shell transverse, oval-globular, or elongated, multilocular; 

 chambers transverse, surrounding the axis, and successively cover- 

 ing one another ; aperture very small, situated at the base of the 

 last whorl, orbicular, or oblong. 



Lamarck states that he possesses some milliolites, (or rather 

 milliolitce,) in the recent state, which were found on fuci, near the 

 Island of Corsica ; but all the species he describes are fossil. In 

 that state they occur in such vast abundance as to form the 

 principal part of the stony masses of some of the quarries near 

 Paris. 



The size of these tiny shells scarcely exceeds that of grains of 

 millet (whence their name) ; some are globular, inclining to oval, 

 others oblong, or somewhat triangular. Their spire turns round 

 an axis perpendicular to the plane of the whorls, and much longer 

 than the transverse, or horizontal diameter of the shell ; which is 

 just the reverse of what takes place with the planorbes, ammo- 

 nites, Sfc. The chambers, which are considerably broader than 



* From ipharula, a little ball. t From mitlium, millet. 



Vol. XVI. R 



