241 
of the actinopharynx, and at the basal disc as also in the collar 
region. Thus they are probably scattered. The tentacles are very 
numerous, I counted in the largest specimen about 160 tentacles. 
They are more cylindrical than conical, the inner tentacles consider- 
ably longer than the outer, one part of which are very small. Al¬ 
most the whole disc is provided with tentacles. The actinopharynx is 
long and furnished with about 16 longitudinal folds. In the single 
examined (the largest) specimen from Slipper Island there were 2 
siphonoglyphes not symmetrically situated, ordinarily developed and 
provided with aboral prolongations, in two examined Kaipara-spec- 
imens 2 siphonoglyphes were present, in one specimen one siphono- 
glyphe was weak (compare below). 
Anatomical description. The ectoderm of the column is 
ordinarily high and contains numerous giand cells and nematocysts. 
The latter are sometimes a little broader in their basal part than 
in their distal and somewhat curved, their basal part to the spiral 
thread is visible. Their sizes are 12—19 x (about 2 , 5 ) 3—( 3 , 5 ) ///. 
The mesogloea of the column is in the preserved specimens of 
about the same thickness as that of the ectoderm, sometimes thinner, 
sometimes a little thicker. It is fibrillar and contains very numer¬ 
ous cells. The cinclides are invaginations of the ectoderm as well as 
excavations of the endoderm. The circular muscles of the column 
are weak, especially in the region above the collar. There is no 
trace of a sphincter (3 specimens sectioned). The nematocysts of 
the tentacles are numerous and of two kinds, the one agrees in 
its structure with the nematocysts in the column but is somewhat 
larger (17) 19—29 X about 3—4 (5) fi, the other is opaque and 
rib-like and 15—19 X about I,.*) (2) fi in size. The longitudinal 
muscles of the tentacles and the radial muscles of the oral disc 
are ectodermal and rather weak. The ectoderm of the actinopharynx 
is high and thicker than the mesogloea. Its nematocysts are partly 
22—29 (34)X3— 3,5 fi, partly 22—26x 1,5 — almost 2 //, the basal 
part to the spiral thread is visible in the former. 
The mesenteries. I have sectioned transversally the proximal 
half of the largest specimen from Slipper Island. There were in 
the under part of the actinopharynx 50 pairs of mesenteries, of 
which 2 pairs of directives not symmetrically arranged. 8 pairs 
were perfect, between the directives on one side 2 on the other 
Vidensk. Medd. fra Dansk naturhist. Foren. Bd. 77. 16 
