MUSEUM OF COMPARATIVE ZOOLOGY. 125 
what colored on the inside. In that respect it is not quite like the 
bursa of most Ophiurans, which is composed of the lining membrane, or 
layer, of the body-wall. 
The spermatozoa of Ophiocreas adipus after their long immersion in 
alcohol, were doubtless much altered. Strongly magnified, they resem- 
bled little translucent grains of boiled sago, but showed no projection or 
ciliary tail. 
In Fig. 7 the floor of the stomach, St, St, is slit to expose the sper- 
matie pouch, so that the lower portion is separated from the upper one, 
which lies under the radial shield, 4, and whose roof grows closely to the 
ก as in Astrophytons. lt also adheres, as mentioned above, to 
the interbrachial floor of the disk-wall Indeed, it is scarcely free at 
any point save a space along the top of the arm, which forms an oblong 
sinus, The interior of the stomach is lightly marked by radiating 
pleats, and there are also five pairs of strong radiating ridges, a pair over 
each arm, which form partial partitions. 
These brief observations show that Astrocnida, and behind it Astro- 
gomphus, is nearest in relationship to the true Astrophytons. Not only 
does the arm-covering, with its double rings of minute hooks, shadow 
forth an affinity, but the internal structure, with a pouched stomach, 
and ovaries lying free in the general body-cavity, is similar; while the 
want of adhesions on the under side of the stomach and the closed ring- 
tube about the mouth remind us of the Ophiurans. But, in reaching 
after some form which may bridge the way to these last, we find, as gen- 
erally happens in the animal kingdom, no piece that will fit. Ophio- 
creas, which is properly a simple-armed Astrophyton, is not intermediate. 
It is a synthetic form. It has the teeth of Euryale, the pleated stomach 
suggestive of Gorgonocephalus, the genital bursa and ovarial tubes sim- 
ilar to, yet not the same as, those of Ophiurans in general, the arm-plates 
that recall Ophiomyxa; nay, one Astrophyton character, the adhesion 
of the stomach to the disk-wall, is carried farther than in Astrophyton 
itself. 
In conclusion, it is proper to suggest a slight resemblance which the 
branching Astrophytidæ have to the order of Starfishes. This is in the 
stomach-pouches filled with a clotted matter, which suggest the varied 
cœcal appendages characteristic of different genera among Asteroidea. 
