586 
BULLETIN OF THE BUREAU OF FISHERIES 
GREENGILL 
In the winter of 1927-28, the writer collected scallops in western Bogue Sound, 
N. C., which were found to have bluish green gills. Examination of fresh material 
revealed greenish pigment in the epithelial layer of the ordinary filaments. A sketch 
from this fresh material shows an irregular band of pigment (green granules) on the 
sides of the filament near the front. From the arrangement of the granules it does 
not seem that they were grouped in “secretion cells” as Lankaster (1886), Herdman 
and Boyce (1899), and others in Europe, and Mitchell and Barney (1917) in this country 
have reported for greengill oysters. Nevertheless there is reason to believe that the 
greening is of the same nature in oysters and scallops. It appears that with oysters 
the green granules are not always confined to the “secretion cells” (Ranson, 1927). 
As is generally reported for oysters with greengills, these greengilled scallops were in 
very good condition. The very region in which they were found had been abandoned 
by oystermen because the oysters became greengilled. There is much similarity in 
the feeding and location of scallops and oysters (both being forms which live on, 
rather than in, the bottom). 
Although it was not learned whether Navicula osteraria was present, because it 
has been reported with such remarkable uniformity in connection with the greening 
of oyster gills, it may be taken as indicated that it occurs in this region of greengilled 
oysters. Certainly there is no reason to believe that food organisms or material which 
would color the gills of scallops would not affect those of oysters and vice versa. 
Although I have seen no other references to the greening of scallop gills, that is not 
surprising in this country, at least, for here the gills are removed from the market 
product and no economic interest attaches to their color. 
LIPS 
The labial palps (fig. 3) may be considered specialized, lobate prolongations of 
the lips. There is a pair of them on the right and left sides of the mouth, between the 
mouth and the end of the gills. The outer palp of each of these pairs is a continuation 
of the dorsal lip, the inner of the ventral. Between them is the oral groove. The 
adjacent surfaces of the palps of each pair are ridged and very elaborately ciliated. 
It is the function of the palps either to transmit to the mouth or to reject as unsuit- 
able the material delivered by the gills. In the selection the muscular movements 
of the palps aid the elaborate sorting action of the complex ciliary arrangement. 
The ciliation of the palps of scallops has been studied and figured by Kellogg (1915). 
For detailed accounts of palps see Churchill and Lewis (1924) and Mathews (1928). 
The lip ridges leading from the palps to the mouth (or the opening into the 
oesophagus) are, in the scallop, most remarkably produced into much branched, 
“tufted” prolongations (indicated in fig. 9c). In life they are active and evidently 
ciliated. As noted by Dakin the branched structures from the two lips interlock 
(or overlap) over the mouth so that there are, in effect, two oral openings, one for 
each groove. 
ALIMENTARY TRACT 
The mouth or opening into the oesophagus is wide and dorso-ventrally flattened. 
From this the oesophagus rapidly tapers and thereafter, bending to the left, continues 
in its narrowed form to join the stomach. The action of the cilia of its epithelial 
lining conveys food and other material to the stomach. 
