'' 



132 



lateral, tinged with light purple ; margin entire ; 

 white with a dark brown muscular impression. f * 

 Bang or , fare, Isle of Man. 



P. PULCHELLA. Forbes in Mag'. Nat. H, 7. p. 59 L 

 f. 61. Ovate, smooth, subpellucid, bluish white with 

 ten or twelve moinliform red rays (becoming by age 

 reddish white and opaque) ; apex acute, submarginaL 

 0,16.. .0,20. Isle of Man. 



P. ANCYLOIDES. Forbes, Annals Nat. Hist. 5. p. 

 108. t. 2./. 16. An. P. GUSSONI. Phillippi. t. 7.f. 7.? 

 Extremely thin, pellucid, rounded, gibbous, white, 

 seeming reticulated when under a lens ; vertex inclining 

 to the margin ; inside bluish white. 0,16. Arrant 

 Wonderfully like a marine Ancylus. 



TRIBE. SEMIPHILLIDIANA, 



GENUS.PLEUROBRANCHUS. 



Dorsal and internal, thin, flat and obliquely ovaL 

 P. PLUMULA. E. p. 291. BULLA. P. Mont. p. 

 214. via. 2./. 5. (animal) andt. 15. f. $.D.p. 478. 

 Inn. T. 8. p. 123. Ovate-oblong, depressed, pel- 

 lucid, thin, glossy yellowish white tinged with brown at 

 one end, the other minutely convoluted on the back or 

 upper part (the convolution making but one turn) 

 strongly wrinkled concentrically, and marked with two 



