GASTROCH^N, 



331 



name of the Watering Pot, and is represented in Fig. 135. It 



inhabits a calcareous tube, thick, solid, of considerable length, and 



nearly cylindrical, presenting at one extremity an opening fringed with 



one or many foliaceous folds in the form of frills, 



and at the other extremity a convex disk, pierced 



with holes like a watering-pot: whence its name,. 



The animal is attached by certain muscles to the 



interior of the tube. Chenu, to whom we are 



indebted for our information respecting this curious 



mollusc, tells us " that the animal which inhabits this 



curious shell was first described by Eussell, whose 



account of it is deficient in the anatomical details, 



which might explain the utility of the holes in the 



disk of the central fissure, and of the spiriform tubes 



found there." We suppose that this arrangement is 



necessary in order to facilitate respiration ; and M. De 



Blainville thinks the small tubes are intended for 



the passage of the fillets which are necessary to fix 



the animal to the body on which it is to live, and 



in such a manner as to admit of its movements round 



a fixed point. 



The animal which inhabits the Aspergillum is 

 elongated, contractile, and only occupies the upper 

 part of the tube, but it can stretch itself out 

 sufficiently for all its wants. Shells of this genus 

 are very rare, although a great number of species are 

 known. They are found in the Bed Sea, and in the 

 seas of Australia and Java. The -shells are generally 

 of a white or yellowish tint ; some have the tube Fig 135 As p er giiium 

 covered with a glutinated sand, mixed with small giniferum (Lamarck). 

 fragments of shells of diverse colours. We know nothing of their 

 habits, and their singular forms have left naturalists in doubt as to the 

 place which should be assigned to them in the method of arrangement. 

 It is only after having recognized the existence of two valves, which 

 was detected with great difficulty just under the disk, and forming part 

 of the sheath in which the animal is encased, that it has been decided 

 to range them with the Tubicola, and with the shells presenting an 

 arrangement analogous or equally singular. These molluscs are, as 



