56 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [350] 
the sand aside, making the burrow larger, and furnish points of resist- 
ance toward which the parts behind can be drawn, or against which 
the head and anterior parts can push in epetinning: the burrow. 
The head, moreover, is extremely changeable in form, at one time 
being spear-shaped, with a pointed tip and thin edges, and con- 
stricted at the tteck; in the next minute broadly rounded; then 
perhaps truncate or even deeply emarginate at the end ; then gr winaily 
losing its distinctness and blending its outlines contmuanalys with 
those of the body; or perhaps shrinking down to a small oval form, 
not more than one-third as wide as the body just back of it. All these 
and many other changes can often be witnessed within a very few min- 
utes, and are so effected as greatly to aid the creature in burrowing 
This worm can also leave the bottom and swim rapidly in the water, 
the body being usually kept up edgewise and impelled forward by the 
undulations of the body, which thus become horizontal. When swim- 
ming in this way the motion reminds one of the swimming of a snake 
oraneel. In addition to the terminal pore, for the proboscis, there 
is a deep lateral slit or fossa on each side of the head, and a large ven- 
tral orifice beneath. The latter is very changeable in form, changing 
from elliptical, long oval, oblong, or hour glass-shape, to circular in rapid 
succession. There are no eyes. Along each side of the greater part or 
the length of the body, the voluminous, transversely-banded lateral 
organs can be imperfectly distinguished through the translucent integ- 
ument, as well as the median cavity, in which a dark pulsating tube can 
sometimes be seen. The lateral organs commence at about the anterior 
fourth in small specimens, but in the larger ones relatively nearer the 
head, for in the largest they originate only six or eight inches back of 
it. The portion in front of the lateral organs is thicker and more cy- 
lindrical than the rest of the body. 
The color of the largest specimens is generally light red or flesh-color, 
with the lateral edges and central band translucent grayish white, the 
lateral organs showing through as dull yellowish transverse branches, 
with diverticula between them; head yellowish. But one large speci- 
men was dull brownish yellow; others are yellowish white, with the 
lateral organs deep chestnut-brown, crossed by white lines. The small 
specimens are generally paler, usually pale flesh-color or yellowish 
white and often milk-white. Some of the diversity in color may be 
due to sexual differences. This species has also been dredged on sandy 
and shelly bottoms in six to eight fathoms in the sounds. 
Dr. Leidy has also described another similar species, from Great Egg 
Harbor, under the name of Meckelia lactea, which I have not been able 
to distinguish, unless it be what I have regarded as the light-colored 
young of MM. ingens ; ‘the white color seems to have been the principal 
character by which it was distinguished from the latter. 
The Meckelia rosea is, however, a very distinct species, but it lives in 
similar places and is often associated with the M. ingens. It has very sim- 
