456 
EDITH M. MUSGRAVE. 
were also present and also tlie four additional apertures form- 
ing tlie four corners of a square (fig. 4, L.ap.), but in the case 
of P. pliospliorea tlie two lateral apertures in close 
proximity to tlie dorsal and ventral apertures in tlie species 
P. rubra were not observed. 
III. 
Healthy freslily captured specimens of P ter oe ides 
spinosum were submitted to injections similar to those 
already described inPennatula, and as the results differed 
somewhat in the two forms, it will be more convenient to 
consider the case of tliis genus separately. As the body- 
wall, and, in fact, the texture of the whole colony in Pteroeides, 
is much stouter, tougher, and more muscular than in Penna- 
tnla, some considerable time elapsed before a carmine injec- 
tion of the dorsal canal about the middle of the rachis caused 
any appreciable difference in the appearance of the colony; 
but after an interval of more than twenty-four hours particles 
of carmine were extruded from four minute dorsal pores near 
to the apex of the rachis, which, as in Pennatula, only 
became discernible after injection. Carmine was also ex- 
truded in the form of minute particles from several pores 
about the base of the stalk (fig. 3) ; of these, one larger than 
the others, and almost medianly situated, had tumid lips, and 
proved later to be the dorsal aperture of the large dorsal 
canal (fig. 3a, B.D.ap.). Four slightly smaller apertures were 
also actively engaged in the extrusion of carmine. 
The day following the lower end of the stalk of the same 
specimen (hereafter known as specimen No. 1), was placed in 
a solution of methylene blue in sea-water, care being exercised 
that the remaining portion of the colony, while submerged in 
clear sea-water, should not be exposed to any material extent 
to the influence of the coloured fluid. This was accomplished 
by placing the stalk into a deep, narrow-necked vessel con- 
taining the methylene blue solution, and carefully introducing 
