MUSEUM OF COMPARATIVE ZOOLOGY. 119 
the body-cavity, and not a closed annular tube. Tt may be seen in 
wider section in Fig. 2. The main stomach, direetly above its own cen- 
tre, passes upward to the roof of the disk as a simple cone, round which 
appear the folds of the radiating pouches (Fig. 1). To give a general 
notion of this complex organ, we may suppose a large loose bag, having 
a hole at the bottom (mouth), and whose periphery is gathered in nu- 
merous radiating folds, leaving, within, a central flask-shaped open space 
communicating directly with these folds ; and, further, that the folds 
are divided into ten lobes, and each lobe is attached at the bottom by a 
radiating adhesion. 
The central cavity of the stomach was empty, but its lobes were 
stuffed with a coagulated, yellowish, pasty substance, which, either sim- 
ple or with reagents, presented no special structure under the micro- 
scope, and which contained no organic remains. 
The ovaries consist of deep, lobed and contorted folds of the lining 
membrane of the disk-wall on its floor, sides, and a portion of its roof. 
These folds are crammed with egg-clusters, so as to resemble puddings 
or sausages (Figs. 1 and 3, 8, à); and, whatever their form, all end by ad- 
hering at their inner margins to the outer ends of the corresponding 
stomach-pouches, whose basal lines of adhesion they also continue along 
the arms, and along the median line of each interbrachial space. As 
has been said before, the body-cavity is thus divided into ten radiating 
compartments freely communicating at their inner ends by large holes 
through the partitions. A genital opening enters each of the compart- 
ments (Fig. 3, 20), Gorgonocephalus, therefore, has no closed bursa, 
with its cluster of genital tubes, but the entire body-cavity, except the 
open (perihæmal) ring outside the mouth, is also the genital cavity. It 
was a similar arrangement that the older anatomists attributed to Ophi- 
urans ; and it is strange that their observations were true only of genera 
they had never dissected. 
As to internal composition, the ovarial lobes are uniform, and every- 
where contain, under a thin, membranous envelope, crowded masses of 
egg-clusters averaging about 1 mm. in length, and separated from each 
other by delicate membranous partitions (Fig. 4). The eggs which com- 
pose each cluster are round, and about + of a mm. in diameter. The 
general envelope, as may be seen in the figure, becomes thicker at the 
free margin, and especially so at points where it grows to the stomach- 
pouches. Its function of supporting the stomach points to its homology 
with those slender threads that suspend the Ophiuran stomach to the 
body-wall I was not able to detect on the surface of the ovarial lobes 
