AGLAJIDvE. 43 



dots, the gills whitish. The individuals were mostly of the same size : 

 length of pleuropodia 7'5 mill., breadth of animal across extended 

 pleuropodia 12 mill., alt. 5'5 mill. 



Besides its smaller size and different coloring, the lack of a pos- 

 terior flagellum on the mantle offers an obvious external difference 

 between this form and G. rubrum. For description of anatomy see 

 Bergh, I. c. 



Family AGLAJID^. 



=Doridiid(E Bergh et at. 



Body oblong, with two dorsal shields separated by a transverse 

 furrow, the head-shield having narrow, free lateral and hind mar- 

 gins, posterior shield or mantle produced backward in two lobes or 

 wings. Foot wide, truncated in front and behind, the sides contin- 

 ued in fleshy parapodial (pleurapodial) lobes which stand erect or 

 recurved at each side of body. Shell internal, posterior, consisting 

 of a flat, solute spiral whorl and a minute spire, the inner rim of 

 whorl calcified, outer part membranous. Gill posterior, on right 

 side, large, bipinnate. Buccal mass very large, without jaws or 

 teeth. Penis with a superficial sulcus ; prostate gland large. 



This family differs from Philinidce and Gastropteridce in the lack 

 of a radula ; from the latter family it is moreover distinguished by 

 the more moderate size of the parapodial lobes, which are not used 

 as swimming organs. 



The following account is largely abridged from Bergh's two ad- 

 mirable papers on Doridiidse. 



Synopsis of Genera. 

 Genus AGLAJA Renier. 



Head-shield without rhinophores or frontal processes. 

 Genus NAVANAX Pilsbry. 



Head-shield with the front lateral angles produced into rhino- 

 phores, as in Pleurobranchus. 



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