578 JAMES F, GEMMILL 
tuediae is put down as occurring at depths of from fifteen 
to seventy-five fathoms. My own records lower the first limit 
to thirty fathoms. While possessing an attaching base and 
capable of adhering weakly to the sides or bottom of an 
aquarium tank, Bolocera appears to live usually on muddy 
bottoms, and is almost always brought up by itself when 
taken with the dredge or on the long lines of fishermen. It 
has great stinging powers, and one has to risk a somewhat 
severe urticaria when handling it alive. 
The sexes are separate and the gonads are at their largest 
in the end of February and beginning of March. Unfortunately 
the females very seldom spawn in captivity. The eggs are 
retained and undergo absorption after a time. Probably 
want of the natural food is a contributing reason. The males 
shed their sperm more freely. 
Only a few eges were obtained in 1916 and 1917, but in 
March 1918 large numbers were extruded by a recently-taken 
specimen. ‘These after floating about m the Bolocera tank 
were duly fertilized, although none of the males at the time 
had emitted a noticeable amount of sperm. 
Maturation must take place just prior to extrusion. Serial 
sections of full-sized ovaries show the eggs with large-sized 
germinal vesicles, but in similar sections of freshly-shed unfer- 
tilized eges the nucleus is so small and inconspicuous that 
I could not detect it. 
The eggs are spherical, 1:1 mm. in diameter, and pink or 
flesh coloured, i.e. of much the same tint as the animal itself. 
They tend to float, and when floating show no polarity as 
regards upper and under sides. ‘They are surrounded by 
a membrane beset all round by small conical bunches of spines. 
The interior is crowded with small granules faintly stainable 
with haematoxylin, small yolk-spheres staining red with 
eosin, and large clear spherules unaffected by re-agents, the 
latter being relatively more numerous towards the centre of 
the egg. In certain methods of preservation (e.g. corrosive 
sublimate followed by graded alcohols) an inner core, about half 
the diameter of the egg, tends to become separated from the 
