206 PLEUROBRANCHUS. 



Pleurobranchus angasi E. A, SMITH, Zool. Coll. "Alert," p. 88, pi. 

 6,f.J2"(1884). 



This may be the P. delicatus of Pease, but there appear to be 

 certain differences in the shells of the two forms which may be of 

 specific value. (Sm.~). 



P. ORNATUS Cheeseman. PL 47, figs. 22, 23. 



Body 3-4 inches long, broadly elliptical, depressed, nearly equally 

 rounded at both ends, color varying from pale buff to a clear red- 

 dish brown, with irregularly disposed blotches of a rich, dark red- 

 brown ; mantle large, extending over and concealing both head and 

 foot, quite smooth, margin thin, entire; dorsal tentacles short, stout, 

 abruptly truncate, finely transversely wrinkled, approximate at 

 their origin, but gradually diverging at their apices ; color reddish- 

 brown tipped with white ; eye-specks black, placed a little distance 

 behind the tentacles, embedded in the integument, but appearing 

 through it; oral tentacles united in front by a thin semicircular ex- 

 pansion which forms a veil concealing the mouth, and which is car- 

 ried in advance of the foot ; mouth roundish, with fleshy lips ; buc- 

 cal plates two, regularly reticulated ; odontophore with numerous 

 rows of similar unciform teeth. Branchial plume placed in the 

 groove between the foot and the mantle, very large, composed of 

 about 22-24 pectinations ; foot oblong, thin and flexible, pale waxy 

 white. 



Shell internal to inch long, squarish oblong, thin and mem- 

 branous, semitransparent, slightly iridescent, closely marked with 

 somewhat irregular concentric stride or folds; color varying from 

 nearly white to pale pinkish or tawny brown. Spire minute, ob- 

 scure, mouth occupying the whole of the under surface (Cheesem.). 



Auckland Harbor, New Zealand, under stones between tide marks ; 

 also near Waiwera and in Hauraki Gulf (Cheeseman). 



Pleurobranchus ornatus CHEESEM., P. Z. S., 1878, p. 275, pi. 15, f. 

 1, 2. BUTTON, Man. N. Z. Moll., p. 124. 



(East Indian and Indian Ocean Species). 



P. CORNUTUS Quoy & Gaimard. PL 23, figs. 28, 29, 30, 31, 32. 



A very small, ovate species, remarkable for the strong anterior 

 sinus of the dorsal shield, out of which the two tentacles pass. The 

 left tentacle is longer, but this seems to be accidental. The veil 

 forms two diverging horn-like processes ; mouth projecting, foot sur- 



