338 BIOLOGICAL SURVEY OF 



1869, Porella hella Busk." As Whiteaves ' material was 

 identified by Norman, I take it that his record is correct. 

 Whether Verrill's record (1879, p. 192) is correct may be 

 doubted. 



The zooecia measure on the average 0.7 mm. long by 0.5 mm. 

 wide, and the primary aperture 0.12 mm. long by 0.15 mm. 

 wide. 



Smittina xovanglia 11. sp. PI. 9, figs. 8-9 ; pi. 13, figs. 7-8 ; 

 pi. 14, fig. 5. This species, which is apparently undescribed, 

 bears a very close resemblance to S. hella in its general ap- 

 pearance and mode of secondary calcification, but the 

 ooecium is entirely imperforate and is not overgrown by the 

 secondary crust; the lyrula is variable, usually smaller and 

 shorter, and is often rounded or pointed on its free border 

 (sometimes it is scarcely evident), and the cardelles are 

 larger. It occurred at dredging stations 56 and 62, near the 

 entrance to Sommes Sound, at about 60 feet, in the Mount 

 Desert Island collections. I have specimens also from Great 

 Round Shoal, east of Nantucket Island, at 8 fathoms, and 

 from Georges Bank. 



Zoarium forming a single layer on stones and shells, rather 

 coarse in texture, white to light yellowish brown in dried 

 specimens. Zooecia large, coarsely and unevenly punctured 

 by large tremopores, the frontal wall becoming very thick 

 almost from the beginning of calcification; the marginal 

 grooves moderately distinct in younger stages. The primary 

 aperture about as in hella, though a little larger and longer 

 in comparison. The lyrula is usually less prominent, smaller, 

 sometimes rectangular, but usually with rounded corners, fre- 

 quently roughly triangular, and sometimes reduced so as to 

 be scarcely evident; the hinge denticles are much stronger 

 than in hella, so that between them and the lyrula the oral 

 border appears bisinuate. The thin operculum bears a pair 

 of curved sclerites well separated from the border. A small 

 rounded or oval avicularium behind the lyrula becomes en- 

 closed within the secondary aperture, which is pyriform and 

 bears a deep sinus in its proximal border. Ooecium moderate 



