30 



A MONOGRAPH OF THE. 



inhabiting the coralline region (or region of flexible zoophytes) is not very far inferior. 

 Beyond this region the Nudibranchs to be met with are few, and chiefly belong to the genera 

 Tritonia and Idalia. Several species are common to the littoral and coralline zones, but only 

 one, Doto coronata, has yet been found to inhabit all the three regions. Nearly all the Borididm 

 {Idalia excepted) are littoral, a very few only reaching to the coralline zone. The Bolides are 

 pretty nearly divided between the two. 



NUMBER OF SPECIES IN EACH GENUS. 





Doridid^e. 





Doris 





21 



Goniodoris 



. 



2 



Triopa . 



. 



1 



iEgirus 





1 



Thecacera 





3 



Polycera 



. 



3 



Ancula 



. 



1 



Idalia 



TltlTONIADiE. 



6 



Tritonia 





4 



Scyllaea 



EOLIDIDJE. 



1 



Lomanotus . 





2 



Dendronotus 





1 



Doto 





3 



Eolis 



. 



41 



Embletonia . 





3 



Fiona . 





1 



Hermsea 





2 



Alderia 



# 



1 



Proctonotus . 





1 



Antiopa 





2 



38 



57 

 100 



