1891]. Zoology. 665 
semilunar valves constructed on the same plane are present in the 
tentacular canals; that a pair of auditory vescicles are present on each 
radial nerve where it emerges from the calcareous pharyngeal ring, 
and these are probably functional in the adult; the so-called eyes of 
Synapta vittata are undoubtedly sense organs, and the pigment spots 
in other forms are probably the same. These spots in S. witfata have 
a rich nerve supply. 
Genito-Intestinal Canal in Trematodes.—S. Goto confirms 5 
Ijima’s account of a canal connecting the oviduct, in the ectoparasitic 
Trematodes, with the intestine. His studies have been made on eleven 
species representing four genera. 
Fertilization in the Cestodes.—Pintner ê has been very fortu- 
nate in finding two proglottids of Anthobothrium musteli in copula, ‘and 
ascertained that a true cross fertilization was taking place. He also 
found another proglottid of the same worm in which the penis had 
entered very deeply the vagina of the same joint. These observa- 
tions show that both close and cross fertilization occurs in these an 
possibly in all Plathelminthes. 
Regeneration in the Oligochztes.—Miss H. Randolph has 
studied the reformation of the tail in Lumbriculus.? She finds that 
the processes are much like those of the growing embryo, except in 
regard to mesoderm. When fission occurs the violent contraction of 
the longitudinal muscles curves the ectoderm and entoderm towards 
each other, and then a union between the two is effected. The more 
rapid: growth of the ectoderm produces the material for the procto- 
deum. The ectoderm gives rise to the ventral nerve chain and the 
lateral nerve line, and between these occur two other anlagen, which 
correspond in position to the ventral sete and nephridia, but Miss 
Randolph has not traced them out. The mesoderm arises chiefly from 
large cells (neoblasts) in the region of the ccelomic epithelium of the 
ventral long muscles. These neoblasts represent the chorda cells of 
Semper, and occur in every segment except a few anterior. From 
these arise the embryonic mesoderm of the newly forming tail. It 
soon becomes arranged into a median and two lateral elements. The 
median becomes the ventral mesentery, and the walls of the ventral 
blood vessel; the lateral elements form all the lateral mesodermal 
structures except the circular muscles. These last arise from certain 
cells whose origin was not traced. 
5 Zool. Anzeiger, Vol. XIV., p. 103, 1891. 
6 Arb. Zool. Zool. Inst. Wien., IX., 57, 1890. 
1 Zool. Anz., XIV., 154, 1891. - 
