CALYPTR^ID^. 2 1 1 



verse striae. Palaeozoic. A connecting link between Yanikoro 

 and Neritopsis ; the former having the columellar lip smooth, the 

 latter insinuated in the middle, or provided with two strong 

 teeth, while Naticodon has only one tooth ; as regards the thick- 

 ness of the shell this transition seems equally to hold good. N. 

 spiratum, Sowb. (Ixiv, 76). Carboniferous; Europe. 



Family CALYPTR^ID^. 



Shell limpet-like, with the apex more or less spiral ; interior 

 simple, or divided by a shelly process, variously shaped, to which 

 the adductor muscles are attached. 



Animal with a distinct head ; muzzle lengthened ; eyes on the 

 external bases of the tentacles ; branchial plume single. The 

 rostrum is prominent and split, iDut non-retractile. 



The bonnet-limpets are found adhering to stones and shells ; 

 most of them appear never to quit the spot on which they first 

 settle, as the margins of their shells become adapted to the 

 surface beneath, whilst some wear away the space beneath their 

 foot, and others secrete a shelly base. Both their form and 

 color depend on the situation in which they grow ; those found 

 in the cavities of dead shells are nearly flat, or even concave 

 above, and colorless. They are presumed to feed on the sea- 

 weed growing round them, or on animalcules; a Calyptrsea, 

 which Professor Forbes kept in a glass, ate a small sea-slug 

 (Goniodoris) which was confined with it. Both Calyptrsea and 

 Pileopsis sometimes cover and hatch their spawn in front ot 

 their foot. 



The use of the calcareous lamina, which is the first stage in 

 the formation of a columella, is to support the viscera and 

 separate them from the foot or locomotive organ. 



GrALERUS, Humphrey. 



Syn. — Sigapatella, Siphopatella, Lesson. Mitella, Leach. 



Distr. — Tropical and subtropical. G, Chinensis, Linn. (^Ixvi, 

 22, 23). Fossil, L. Cretaceous — . 



Shell depressed subconical, spiral, summit subcentral, aperture 

 very large, basal, with a subspiral broad lamina adhering to the 

 left margin. Animal with bilabiate muzzle, buccal appendages 

 short, rounded; a slightly developed, plain-edged neck-lobe; foot 

 auriculate in front. 



GALEROPsis, Conrad. Spire more elevated. G. excentricus, 

 Gabb. Eocene. 



Infundibulum, Montfort. 



Syn. — Trochita, Schum., 1817. Cl^^peola, Gray. Trochella, 

 Gray. 



Distr. — Mostly tropical and subtropical. I. .'ipirata, Forbes 

 (Ixvi, 24, 25). Fossil. Tertiary; T. S., West Indies. 



