CTENOPHORES OF THE ATLANTIC COAST OF NORTH AMERICA 3 
is in the plane of the pole-plate, while its narrow axis is in the plane of 
the tentacles when these are present. This buccal chamber is commonly 
called the “stomach,” but its walls are of ectoderm and bear cilia, which 
are especially well developed in the Beroide, where they occur in linear, 
longitudinal areas extending from the lips inward. This chamber is 
certainly a food receptacle, and we will call it the stomodzeum. 
The stomodzum leads into the entodermal part of the gastric cav- 
ity, a laterally compressed chamber called the funnel or infundibulum. 
The wide axis of the funnel is perpendicular to that of the stomodeum 
and it lies in the plane of the two tentacles to the basal-bulb of each 
of which it sends a canal. It also sends a canal upward to the sense-organ, 
and this axial vessel, which is called the funnel-tube, opens by a pair of 
excretory pores on two diagonally opposite sides of the pole-plate. Inthe 
Beroide there are two lateral funnel-tubes, one to each excretory pore. 
Tr 
1. 
Fic. 1.—Diagram illustrating characters of central part of gastro-vascular 
system of ctenophores. 
Fic. 2.—Diagram showing character of canal-circuits in Lobate. Tentacles, 
tentacular canals, ciliary combs, and auricles are omitted. 
In addition to the two tentacular vessels and the axial funnel-tube, 
the funnel gives rise to four interradial vessels, which arise typically at 
an angle of 45° with the stomodzal and funnel axes. In the Cydippida, 
however, the four interradial vessels do not arise directly from the funnel, 
but the funnel-chamber gives rise to a pair of side tubes called the per- 
radial vessels, pr, figs. 4 and 5, pages 11 and 12, from the sides of which 
the four interradial canalsarise. In any event the four interradial canals 
soon bifurcate and each of their eight adradial branches leads to a row of 
