264 LIFE BY THE SEASHORE. 



(3) Gills absent, processes numerous, simple or branched, tentacles 

 with sheaths. 



Body narrow elongated,^ 



CcTed, = k'"" arb 

 with branched sheaths] 

 Body narrow and small, \ ID. coronata, processes 



Esses unbranched, In/ with 5 to 6 rows of 



and massive, ten- [ tubercles and a ter- 



5 in plain sheaths] [ minal one. 



(4) Gills absent, processes linear or fusiform placed along sides of 

 back, tentacles 4 without sheaths. 



(E. papillosa, 18 to 24 

 transverse rows of pa- 

 pillse, body broad. 



Body elongated, tapering 



1. 



behind with numerous I Eolis 

 simple papillae or pro- J 

 cesses . . J 



E. coronata, papillae in 6 

 to 7 clusters at each 

 side, dorsal tentacles 

 coronated. 



E. rufibranchialis, dorsal 

 tentacles wrinkled, pa- 

 pillae red in 6 to 7 

 clusters. 



OUTLINE CLASSIFICATION OF GASTEROPODS. 



I. The Chitons, primitive forms very different from ordinary 

 Gasteropods. 



II. Zygobranchs, limpet-like forms. 



III. Azygobranchs, forms with coiled shell, single gill in front 

 of heart. 



(a) Forms with unnotched shells, such as the periwinkles, the 



tops, and others. 



(b) Forms with notched shells, such as the whelks, dog-whelks, 



and others. 



IV. Opisthobranchs, forms often without shell, gill behind the 

 heart. 



(a) Forma with shells (Tectibranchs). Of these only the sea-hare 



has been described. 



(b) Forms without shells (Nudibranchs), the different kinds of 



NOTE ON DISTRIBUTION. 



The sea-hare is commoner in the South than in the North, and is 

 said to be especially abundant at Weymouth and Torbay. Of the 

 remaining sea-slugs described in this chapter, certainly the majority 



