GASTEROPODA. 133 



Animal with a long retractile proboscis ; tentacles close together, slender, 

 inflated at the tips ; eyes immersed at the bases of the tentacles ; operc. lobe 

 ample, unsymmetrical ; foot truncated in front. Ranges to 80 fathoms water. 

 3 Brit. sp. Norway. 



Fossil. ? sp., Miocene — . Brit. (Crag). 



C^cuM, Fleming. 



Si/n., corniculina, Miinster. Brochus, Bronn. Odontidium, Phil. 



Ti/pe, C. trachea, PL IX, fig. 5. Young sp., fig. 6. 



Shell at first discoidal, becoming decollated when adult ; tubidar, cylindri- 

 cal, arched ; aperture round, entire ; apex closed by a mammiUated septum. 

 Operc. horny, many-whirled. Lingual teeth, ; uncini, 2, the inner broad 

 and serrulated. 



Distr., Brit., 2 sp., 10 fathoms. Medit. 



Fossil, 4 sp. Eocene — . Brit., Castelarquato. 



Vermetus, Adanson. Worm-sheU. 



Si/n., siphonium. Gray. Serpuloides, Sassi. 



Types, V. lumbricalis,-Pl. IX., fig. 7. 



Shell tubular, attached ; sometimes regularly spiral when young ; always 

 irregular in its adult growth ; tube repeatedly partitioned off ; aperture round ; 

 operc. circular, concave externally. 



I>istr., Portugal, Medit., Africa, India. 



Fossil, 12 sp. Neocomian — . Brit., Trance, &c. 



? Sul-genus. Spirogli/phns, Daud. S. spirorbis Dillw. sp., irregularly 

 tubular ; attached to other shells, and half bm-ied in a furrow which it makes 

 as it grows. Perhaps an annelide ? 



SiLiauARiA, Brug. 

 Etym., siliqua, a pod. 

 Type, S. anguina, PI. IX., fig. 8. 



Shell tubular ; spiral at first, in-egular afterwards ; tube with a continuous 

 longitudinal slit. 



Distr., 7 sp. Medit., N. Australia. Found in sponges. 

 Fossil, 10 sp. Eocene — . France, &c. 



ScALARiA, Lam. Wentlc-trap. 



Etym., scalaris, like a ladder. Type, S. pretiosa, PI. IX., fig. 9 (= T. 

 scalaris, L.) 



Shell, mostly pure white and lustrous ; turreted ; many-whirled ; whirls 

 round, sometimes separate, ornamented with numerous transverse ribs ; aper- 

 ture round ; peristome continuous. Operc. horny, few-whirled. 



Animal with a retractile proboscis -like mouth ; tentacles close together, 

 long and pointed, with the eyes near their outer bases ; mantlc-margiu simple, 



