102 AMERICAN MARINE CONCHOLOGY. 



epidermis yellowish ; spire obtuse, elevated ; suture canaliculate ; 

 aperture narrow above, wide and rounded below ; outer lip sharp, 

 entire, advanced in the central region, with a fissure posteriorly. 



Length 3, diam. 1.5 mill. 



Casco Bay, Me. 



This species has not been figured, and I am not acquainted 

 with it ; nor has it been found since the date of the original de- 

 scription. 



2. B. SOLITARIA, Say. Fig. 206. 



Journ. Philad. Acad., ii. 245. 1822. 

 Sulla insculpta, Totten, Am. Journ. Sci., xxviii. 350, f. 4. 1835. 



Shell small, thin, fragile, pellucid, oval, impressed at the top, 

 with numerous microscopic revolving lines; spire none, but in its 

 place a pit ; aperture narrowly linear above, wide below ; umbili- 

 cus none ; white. 



Length 9, diam. 6 mill. 



Whole Coast. 



3. B. OCCULTA, Mighels and Adams. Fig. 207. 



Proc. Bost. Soc. Nat. Hist., i. 50. 1841. 

 Bulla Eeinliardi, Moller, Ind. Moll. Green., 6. 1842. 



Shell small, of a dingy-white color, ovate-cylindrical, covered 

 with very minute transverse striae, and with indistinct striae of 

 growth ; spire concealed ; labrum extends a little below the spire, 

 nearly straight above the centre, regularly rounded below and at 

 base ; aperture narrow at the upper part, rather broad at the base. 

 Length 5, diam. 3.75 mill. 



New England to Greenland. (Eur.) 



Mr. Jeffreys says this is identical with Cylichna striata, Brown, 

 1827. 



Genus CYLICHNA, Loven. 

 Ind. Moll. Scand. 10. 1846. 



In this genus the tentacular lobes are connate, indistinct; 

 eyes sessile on their front bases ; mantle with a thick posterior 

 lobe, partially closing the aperture of the shell. 



The species chiefly inhabit deep water, and the genus is of 

 world-wide distribution. 

 1. C. ALBA, Brown. Fig. 208. 



(Volvaria.) Brit. Conch., 3, t. 88, f. 43-44. 1827. 

 Bulla triticea, Couthouy, Bost. Journ. Nat. Hist., ii. 88, t. 2, f. 8. 1838. 

 Bulla corticata, Moller, Ind. Moll. Green., 6. 1842. 



Shell polished, cylindrical, rather solid; spire slightly de- 



