4 CALIFORNIA ACADEMY OF SCIENCES. 
tinct in the others. In segment VI the forking is so deep that it nearly 
divides the vessel in two (Fig. 4, I to VI). In segment VII the forking is 
perfect, and from that toward the end of the body we find in every segment 
two distinct pairs of perigastric vessels. Each of these vessels again are forked at 
the apex, and feathered—that is, besides the forking at the apex, it emits two pairs 
of side branches. All these secondary perigastric vessels end blindly in the peri- 
gastric cavity and do not connect directly with the ventral vessel (Fig. 5). 
The ventral vessel is not pulsating. It is forked in segment VIII, the 
forks again uniting with the dorsal vessel in the cephalic lobe (Fig. 4). A similar 
forking of the ventral vessel is known in the other genera of Lumbriculide. The 
two forks of the dorsal vessel are again connected by secondary perigastric vessels 
(Fig. 4, v. pr. v.), which, however, in no way connect with the dorsal vessel or its 
secondary perigastric vessels. In hynchelmis limosella* as well as in Phreatothrix + 
the contrary takes place. Here the secondary ventral vessels connect the ventral 
forks with the dorsal pulsating vessel. My observations on the transparent Svtroa 
satisfy me positively that my above description is correct, and that the dorsal and 
veutral vessels are not united in those segments. The blood in all the vessels is 
lively yellowish-red. 
The alimentary canal is extremely simple, consisting of a simple duct. In the 
twelve anterior segments this duct is narrow and quite pellucid, but in the thir- 
teenth segment it is considerably enlarged and continues so toward the posterior 
part of the body. In the same segment we first meet with gastric vessels. 
The nervous system resembles that of Lhynchelmis. The two ventral nerve 
cords are, as in Lelipidrilus, connected by numerous anastomosing commissures. 
The cephalic ganglion is rather long and narrow. No lateral nerves project from the 
ventral nerve cord. 
Generative System.—Vhe sexual organs are of two kinds—generative and recep- 
tive. The generative include: 
Testes, ovaries aud albuminiferous gland. 
The receptive are: Efferent ducts, with atriwn and seminal vesicle; oviducts and 
receptacles, 
“Vespovsky: Anatomische studien. Rhynchelmis, Zeitsch, f. w. Zool. Ba. XXVII, Taf. XXI, Fig. 1. 
+The sane. Ueber Phrcatothrix. Same, Bd. XXVII, Taf. XXXIX, Fig. 2. 
