the upper part of the nucleus, with which it communicates by means of two apertures, one of which is simple and the other double.
Besides the above mentioned apertures in the nucleus, another oblong one is placed on the right side for the passage of the oviduct; and another on the opposite side, probably serving for excretion. Oviduct filiform, including small remote globules.
Vascular System. Composed of a heart, branchia, and artery. The heart is placed between, and in contact, with the branchia and artery. Branchia with from twelve to sixteen perfoliated appendages. Artery extended from the heart to its termination near the jaw, where it is surrounded by four tubercles; in its course it passes through the interstice of the double ganglion. A branch arises from this principal artery, immediately before the last mentioned ganglion, furnishing the dorsal fin with blood by means of numerous smaller anastomosing branches, exhibiting, in that fin, a reticulated appearance.
Obs. In some species of this genus a lateral vermiform organ is superadded; when this occurs, a second branch arised from the principal artery to supply it with blood.
Generative Organs. A vermiform organ is attached to the left side of the body composed of three parts; of which, one is placed above, and seems intended to protect the others; the second is short, cylindrical, straight; the third, elongated, vermicular, attached to the base of the second. This is probably the generative part of the male. The species furnished with an oviduct may be females, as this part is placed on the side opposite to that of the vermiform organ, so as to facilitate the connection between the sexes.
