11 



we have felt necessary to make, not only includes genera differing so ma- 

 terially from each other that they might be regarded as types of separate 

 families, but species which should constitute separate genera. Neither 

 Dr. Gray, Professor Forbes, nor the Messrs. Adams agree as to the natural 

 affinities of the Lamarckian Macrostomata, and the discrepancy of these 

 authors' views leads me to the conviction that the time is not yet ripe for 

 deciding their exact place in the system. The genera are — 



Haliotis. Neeitopsis. Velutina. 



Stomatella. Narica. 



Genus 1. HALIOTIS, Linnceus. 



Animal ; shaped like the shell, its head terminating in a short 

 muzzle, and bearing two subulate tentacles and two stout eye 

 peduncles at their external bases ; a fimbriated lobe between 

 the tentacles, apparently continuous with the fimbriated and 

 cirrhated lateral lobes of the body ; lateral cirrhi numerous ; 

 foot very large, oblong, rounded at the extremities, bearing on 

 its upper extremity a rudimentary operculigerous lobe, but no 

 operculum; branchial plumes, two. (Forbes.) 



Shell ; ovate, ear-shaped, flat, with a small, lateral, depressed 

 spire, pearly and richly prismatic within, roughly ribbed or 

 wrinkled without, rarely smooth ; left side more or less angu- 

 lated, perforated along the angle by a row of holes ; left lip 

 inflexed, flattened ; right lip simple ; aperture very large, wide 

 open. 



Haliotis is curiously intermediate in its characters between the Tarli- 

 nacea, or Troclms family, and the tribe of fissured Limpets. On referring 

 to our figure of //. tuberculata in Plate 7, it will be seen that the animal 

 is encompassed by a cirrhated lobe, and it also possesses, as in Troclms, 

 a head-veil ; but on the other hand, the branchiae are as plumes in con- 

 nection with filaments passing through a slit in the mantle, over which the 

 shell is slit as in Fissurella and Emarginula, and, as we have just seen, in 

 S'diquaria. The number of pallial filaments being alike in any individual 

 of the same species through all its stages of growth, the shell has only so 

 many of its holes open at one time ; as the filaments advance with the 

 growth of the animal, new holes are formed in the additions made to the 

 shell, and the old ones are filled up. 



The interior of the ' Ear Shells ' is lined with a pearly nacre of peculiar 



