281 
they ave somewlmt broader (and longer) than in A. aurita, but 
they are.not lobed proximally as in the typieal A. flavidula ; this 
possibly may be owing 
to the faet that the 
preserved specimens are 
not completely grown 
(the largest ones are ca. 
9 cm. in diameter). — 
The gonadial radius is 
ca. 2 1 5 — 1 /a of the radius 
of the disc. The inci- 
sions of the disc-margin as in A. aurita and flavidula. — The 
canals are comparatively broad; they run somewhat sinuously and 
lather frequently they send out short blind branches. The branches 
of the canals anastomose exceedingly often; towards the disc-margin, 
in consequence, there are a great many short meshes, more than 
in the case of the typieal A. flavidula. In A. aurita, as known, 
the branches are few and narrow and do not anastomose or rarely 
ao so. In this regard the Greenlandic form has some likeness with 
A. limbata Brandt, but there is no trace of£secondary incisions in 
