DEVELOPMENT OF CUCUMARIA ECHINATA 185 
chromatic substance gathered on one side of the egg in the form 
of a dish. 
Male Gonad.—I am unable to give any detailed account 
of the male gonad. In the specimens collected during March 
I found spermatogonia and spermatocytes near the germinal 
epithelium, while the central part of the tube was filled with 
unripe spermatozoa or probably spermatids. In the breeding 
season the internal space of the tube is filled with ripe sperma- 
tozoa, only a thin layer of larger cells—probably spermatocytes— 
being found near the germinal epithelium. Radiating bunches 
of spermatozoa, termed by Mortensen Spermatogemmae, 
were found in C. glacialis (82, p. 715, Pl. xxxi, fig. 28) and 
were also observed in C. ijimai. 
Genital Papilla.—The genital papilla is situated im- 
mediately behind the tentacular crown along the mid-dorsal 
line. A very singular case is noticed by Ludwig (20, 1887, 
p- 1233), who observed that in C. crocea the papilla is located 
far backwards, in extreme cases 8 mm. back and far from the 
tentacular crown in an individual, which measured 40 mm. in 
length, and 8-5 mm. in another individual, 42 mm. long ; that 
is one-fifth or more of the body length. 
But a more noteworthy fact about the genital papilla was 
discovered by Edwards (18, 1910, pp. 838-9, PI. xiii, figs. 2-5). 
He found in C. frondosa that the male genital papilla is 
subdivided into from four to thirty or more parts with a general 
average of ten, each branch ending in a terminal pore. ‘The 
papilla in females is usually simple, ending in a single pore, but 
sometimes, though rarely, two or five pores may be met with. 
Further, the same author (14, 1910, pp. 599-608, Pl. xix, fig. 1) 
proved the presence of a similar feature in such allied species 
as C. californica, C. miniata, and C. fallax. 
C. echinata offers another example of the same thing. In 
a male specimen which I examined the genital pores were at 
least fifty in number, while in females there were from five 
to about twenty-five pores. Previous to branching, the end 
of the genital duct is dilated into a wide cavity just below the 
cluster of minute papillae. This cavity, as well as the branched 
canals, is lined with a ciliated epithelium followed by a thin 
