Morse.] 350 [March 19, 
of the individual. Hancock} however was inclined to believe the 
sexes united in all the forms coming under his observation. Oscar 
Schmidt? also says that in Terebratula the testicles and ego stocks 
are united in the same individual. 
After patient study of these parts, I believe that in all the Brachi- 
opoda the sexes will be found to be separate. In Lingula the sperm- 
aries occur in the perivisceral cavity, in masses like the ovaries. 
Having studied them alive it was found that while in some individ- 
uals the ovarian masses nearly filled the perivisceral cavity, in others 
spermaries occupied similar positions. 
As Discina presents precisely the same characters in the ovaries 
springing from the vascular membranes, and filling the perivisceral 
cavity, it is reasonable to suppose that the spermaries correspond in 
position with those of Lingula. 
A careful study of Terebratulina, lately made during its breeding 
season, shows also that in this form the sexes are distinct. While 
some specimens revealed the vascular sinuses filled with egos, and 
even where the eges had escaped by dehiscence the scars could be 
seen, in others the sinuses showed no traces of eggs, but on the con- 
trary were filled with a creamy mass, slightly granulated, the borders 
of these masses being highly ciliated, and when crushed or separated 
under the compressor, bunches of spermotozoa and single ones were 
revealed. ‘This probably represents the ovigerous mass of Hancock. 
In several females examined, the eggs were attached in clusters to 
the genital band, even to the very edge of the mouths of the segmen- 
tal organs. And in several males the spermaries were likewise 
attached in clusters to the genital band, and in such masses and so 
close to the segmental organ that the accessory vescicle of Huxley 
was obscured by them. 
The masses of spermaries adhering to the genital band, and float- 
ing free in the pervisceral cavity, presented some curious features. 
They assumed the shape of long filiform appendages, attached by 
common centres to the genital band, and surrounded by an almost 
imperceptible cellular mass. The threads widened gradually to their 
distal extremities where they ended bluntly, and were capped with a 
few large brownish cells. ‘The spermatozoa were thickly clustered in 
blunt fusiform masses at the extremities of the threads, forming a 
sort of brush. The same brownish granules appeared in the sinuses, 
1 Hancock, ibid., p. 824. 
2 Zeitschrift fir ges. Naturwissenschaften, 1854, p. 325. 
