520 PROCEEDINGS OF THE ACADEMY OF [1899. 



Doridopsis herpetica Bergh. 

 Doris compta Pse. 



Beautiful pearl gray, with spots of same color, but 'darker. 

 Rhiuophores and sixfold branchial rosette with faint yellowish 

 tinge. Foot and under surface of mantle pearl gray with small 

 spots. Labial tentacles small, whitish. Body slightly trans- 

 parent, showing reddish intestines. Pharynx long, cylindrical ; no 

 jaws ; no radula. 



Pease's plate (Doris compta, Amer. Jour, of Conch., 1871-72, 

 PI. 4, fig. 1) is fairly like the living animal, but he is mistaken 

 in supposing that the mantle edge is pei'manently and regularly 

 indented. The animal is sluggish in its movements, but con- 

 stantly alters its shape; it is sometimes elongated and sometimes 

 oval, and can wrinkle and undulate the edge of the mantle at 

 will. 

 Trevelyana citrina Bergh. 



One specimen obtained at Apia in July. It corresponds accu- 

 rately in color and other external characters with Bergh' s descrip- 

 tion and plate in Semper' s Reisen} (II, 2, PI. xli). 



With regard to this and all other tropical Polijceridcc which I 

 have seen, I would observe that the expression non-retractile, 

 applied to the rhinophores and branchise, is only comparatively 

 true. In Dorididce the branchiae, when touched, disappear 

 entirely, reemerge slowly, and are, as a rule, invisible in alcoholic 

 specimens. In the Polyceridce they generally remain outside in 

 alcoholic specimens, but Avhen touched in the living animal, retract 

 themselves into a pocket, though perhaps less thoroughly, and for 

 a shorter time than in Dorididce. But to say that a genus or 

 family is characterized by non-retractile branchise may lead an 

 observer into error. 

 Cyerce nigra Bergh. 



This beautiful animal appears to be common, as I captured 

 numerous specimens at Apia and Manono. It crawls rapidly, but 

 I have not seen it swim. When it is walking its many cerata are 

 agitated with a motion similar to that of a field of corn under the 

 wind. 



^ By an oversight corrected in another part of Bergh's work the animal 

 figured in the plate is called Nembrotha. 



