NOTARCHUS. 143 



In breathing, the mantle cavity is very forcibly expanded and con- 

 tracted. The snail emits an intensely cobalt-blue liquor, part of 

 which sinks to the bottom, staining the white coral-sand blue ; the 

 rest dispersing in the water. (Mobius). 



N. QUERGINUS Gould. PL 29, fig. 44. 



Length 3 J inches. Body limaciform, elongated, delicately attenu- 

 ated ; the ground color slaty, tinted with wood-color, and longitu- 

 dinally grained with numerous unequal, rusty lines or folds. Ten- 

 tacles very long, linear, truncate at tip, and beset with numerous 

 acute papillae. The papillae on the body are long and branching 

 but becoming more and more simple towards the margin and tail. 

 Eyes distinct, in front of the cervical tentacles. (Gld.). 



Levuka, Fiji Is. 



Stylocheilus querdnus OLD., U. S. Expl. Exped., Moll., p. 226, pi. 

 16, f. 271 (1852) ; Otia Conch., p. 227. 



The peculiar coloration and graining of this animal are something 

 like that of oak wood. 



N. RUFUS Quoy & Gaimard. PI. 16, fig. 7. 



This very small species has the body and neck elongated, as well 

 as the four tentacles ; the foot is quite short. The back appears 

 elevated by the dilation of the borders of the pleuropodial lobes. All 

 of these parts are villose and of a reddish brown color, with the ap- 

 pearance of longitudinal striae. The integument is largely spotted 

 with an almost black brown, fading to smoky in front. Genital 

 furrow black, and a similar line is on the opposite side. Sole of the 

 foot is a very light red-brown. 



Road of Umata, Island of Guam, in 14 fms. (Astrolabe). 



Aplysia rufa Q. & G., Zool. Astrol., ii, p. 314, pi. 24, f. 7. 



The long, filament-like tentacles render it likely that this species 

 is a Stylocheilus ; but no labial processes are mentioned by Quoy. 



N. LONGICAUDA Quoy & Gaimard. PI. 29, figs. 41, 42, 43. 



Length 63 mill. Animal swollen, full and oval, the anterior por- 

 tion elongated, head small; the posterior lengthened and acute. 

 Integument green, with spots of varied red and blue. Dorsal open- 

 ing small, a little posterior, and oblique. Foot very narrow {Rang). 

 Near New Guinea, on free-floating Fucus. 



