450 
EDITH M. ]MUSGEAYE. 
The dorsal aud ventral canals communicate with each 
other by means of numerous apertures in, or short canals 
whicli traverse the vertical septum. 
The two lateral canals are considerably shorter than the 
dorsal and ventral canal ; they also communicate with the 
latter at fi’equent intervals by means of pores in the inter- 
vening septa. In Pteroeides, according to Kolliker, each 
of the two lateral canals is in direct communication interiorly 
with the lumen of the dorsal canal. In all cases the coelen- 
tera of apparently all the zooids communicate by means of 
more or less short canals with the four large central 
canals. In some cases these connecting canals a.re ciliated as 
in Peuuatula inurrayi (Hickson)^ in others they are funnel- 
shaped as iu Protoptilum carpeuteri (Jungersen, 1904, 
p. 53). 
In the stalk, which is usually destitute of zooids, the large 
canals communicate with the exceedingly numerous canals of 
the spongy tissue which line the internal body-wall of stalk 
and rachis, by means of numerous apertures (figs. 13, 14, 
arranijed in longitudinal lines between the insertion of the 
long oblique muscles controlling the movements of the axis. 
In the genus Virgularia, as in other Pennatulids, the 
coelentera of the zooids are iu communication with the 
large central canals, but according to the brothers Marshall 
(1882) supplementary radial canals are also present iu the 
rachis, which do not communicate Avith the coelentera of the 
zooids, but run outwards towards the peripheral tissues. 
In Scytaliopsis (Gravier, 1906) similar tubes arc appa- 
rently present, but in this genus they open dii-ectly to the 
e.xterior. Gravier states that these tubes, with their external 
apertures, are extremely numerous, and contrasts their abun- 
dance Avith the paucity of zooids in this genus. 
It Avould be extremely interesting to determine Avhether iu 
' Professor Hickson has drawn my attention to the presence of 
ceiiain “ciliated” canals in the rachis of Pennatula murrayi. 
These canals ai-e seen in section to he coiuiected hy means of other 
canals which appear to he rmciliated, with the large central canals. 
