520 
homologues of the two membranous appendages described by M. 
Edwards, in the stomach of Lesueuria vitrea. He also described 
the peculiar rod-like cilia noticed by Agassiz, as extending over 
the whole of the inner surface of the stomach, but which the author 
finds, in the specimens examined by him, to be confined to a broad 
band commencing just within the mouth, the remainder of the 
stomach walls being covered with ordinary cilia, which are very 
minute except on the contracted neck, where they become long and 
powerful. Peculiar enigmatical bodies were described as being pre- 
sent in the walls of the ramified cseca which spring from the meri- 
dional canals. They are in the form of minute cushion-like discs, 
which are prominent upon the external surface of the csecal tubes. 
The disc is depressed in the centre, and from this depression a little 
conical elevation projects into the surrounding tissue of the animal. 
The caecal tubes are also partially invested by a peculiar layer which 
extends over irregular spaces of their walls. This layer has been 
regarded as an extension of the ovary, but the author views it as an 
entirely independent structure. It is composed of minute cells, and 
may possibly be an eliminating organ. 
A highly-developed system of capillary tubes was describedin detail, 
as constituting one of the most interesting features in the structure 
of Beroe. These tubes seem to have been noticed by Gegenbaur,* 
who describes a network formed by the anastomosing offsets of cells, 
and which, in very young individuals, represents a system of repeat- 
edly anastomosing tubes. They seem to constitute the same struc- 
ture as that which Agassiz at one timef described as muscular 
fibres in Cydippe — an opinion, however, which lie subsequently re- 
tracts, preferring, in his latest works, J to regard them as merely the 
optical expression of the walls of very large cells. The author has 
no hesitation in maintaining that these are all delicate capillary 
tubes, but without true anastomosis. They are divisible into four 
sets, differing from one another in their deeper or more superficial 
position, and in the general direction of their course. He believes 
that they may be conveniently divided into the following sets : — 
* Studien iiber Organisation und systeraatik der Ctenophoren. Wieg- 
mann’s Archiv, 1856. 
t On the Beroid Medusae of the Shores of Massachusetts. 1860. 
t Contributions to the Natural History of the United States of America. 
Vol. III. 1860. 
