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. somirartaA, Say. Fig. 206. 
Journ. Philad. Acad., ii. 245. 1822. 
Bulla 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. occutta, Mighels and Adams. Fig. 207. 
Proc. Bost. Soc. Nat. Hist., i. 50. 1841. 
Bulla Reinhardi, Moller, Ind. Moll. Green., 6. 1842. 
Shell small, of a dingy-white color, ovate-cylindrical, covered 
with very minute transverse striz, and with indistinct striz of 
erowth; spire concealed ; labrum extends a little below the spire, 
néarly 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. atBA, Brown. Fig. 208. 
(Volwaria.) Brit. Conch., 3, t. 88, f. 48-44. 1827. 
Bulla triticea, Couthouy, Bost. Journ. Nat. Hist., ii. 88, t. 2, f. 8. 18388. 
Bulla corticata, Moller, Ind. Moll. Green., 6. 1842. 
Shell polished, cylindrical, rather solid; spire slightly de- 
