Introduction to Animal Morphology. 309 



outer border with (rarely without, Bela) an anterior notch ; 

 operculum lamelloseornone (Mangilia). 10. Cancellariidae — 

 spiral, ovate shells ; proboscis none ; tentacles far apart, with 

 basal eyes ; operculum none ; foot small, triangular. 



Series III. Hamiglossata — (i-i-i). Families, 11. Muri- 

 cidae — shell with foliaceous or spiny varices, a straight canal ; 

 eyes at the bases of the tentacles ; foot broad, single in front, 

 with leaf-like operculum. Murex has at least three rows of 

 varices ; Typhis has hollow spines ; Trophon a crown of la- 

 mellose varices ; Fusus is spindle-shaped, with an oval mouth ; 

 Pyrula pear-shaped, with a wide opening ; Columbella thick, 

 with a narrow mouth ; Fasciolaria has fusiform shells, whose 

 outer lip is striped transversely. 12. Buccinidae — anterior 

 canal short ; foot large ; border of the outer lip smooth 

 (Buccinum), or toothed (Nassa), often cancellated (Phos), or 

 smooth, oval (Pusionella) ; canal sometimes reduced to a 

 notch (Purpura). In Concholepas the mouth is very wide, 

 and the spire almost none ; Monoceros has a strong tooth on 

 its outer lip ; Magilus, living in coral, has, when young, a re- 

 gular spiral shell, but becomes irregular as age advances. 

 13. Mitridae — shell smooth, with a pointed spire, small mouth, 

 and sharp columellar folds ; proboscis long ; operculum none 

 or small. 14. Olividae — foot large, trigonal, divided into 

 fore and hind lobes ; eyes medial, stalked ; proboscis short ; 

 siphon long ; shell cylindrical, smooth (Oliva, &c.), or lon- 

 gitudinally ribbed (Harpa). 15. Volutidas — rachiglossal ; shell 

 notched anteriorly at peritreme ; columella sharply folded ; 

 siphon long ; proboscis short ; operculum none ; shell oval. 



Sub-section 2. Holostomata — herbivorous, with no 

 siphon, and an entire peritreme. This includes the fol- 

 lowing series ; — I. Ptenoglossa (co . o co ), including, 16. Sca- 

 lariidas — foot small ; eyes near the base of the tentacles ; 

 operculum corneous, paucispiral ; shell aciculate, white, lon- 

 gitudinally ribbed (Scalaria). 17. Solariidae — shell trochiform, 

 last whorl angular, widely umbilicated ; mouth four-angled ; 

 eyes at the base of the lower groove-like hollow tentacles. 

 18. lanthinidae — shell thin, snail-like, bluish, with thin lips; 

 eyes none ; tentacles four ; pelagic inoperculate forms, se- 

 creting a purple fluid ; eggs cohering into a "raft." 



