Revision of the Holothurioidea. 337 
NORDGAARD, 1893; GRIEG, 1889, 1896, 1907, 1907a; PFEFFER, 1890, 
1894; SLUITER, 1895; Kınastey, 1901; WHırteAves, 1901; Horıng, 
1902; ÖSTERGREN, 1903; Schmipr, 1904; and Cvark, 1905. 
The present paper gives a revised description of all the char- 
acters of Cucumaria frondosa including particularly a more ad- 
equate account of the spicules in the body-wall, pedicels and tentacles. 
In addition I have described as new the vestigeal anal teeth and 
the sexual differentiation in the form of the genital papilla (cf. 
Epwarps, 1909), and the detailed order of appearance of the pedi- 
cels from one, or the other, or both sides, of the different radial 
canals. 
Form. — The dorsal surface of the subeylindrical body is more 
flattened than the ventral. The posterior end is rounded, and from 
the expanded oral disc the dendritic tentacles are broadly extended 
in life although contracted in alcoholic specimens (Pl. 13, Fig. 1). 
When irritated, the powerful retractors pull in the introvert, 
and the holothurid becomes more or less ovoid, with deeply wrink- 
led skin. 
Size in centimeters. — Of 120 speeimens in the collection, 
59 individuals are of less than 3 cm in length and are classed as 
young. The following determinations are made from the 61 adult 
specimens. 
Lengthofbody,introvertretracted.Mean 8,755 + 0,319. 
Standard deviation 3,714 + 0,225. Coefficient of variability 42,421 + 
2,59. Range 3—16. Berr, 1892, says that it „may be as much as 
a foot long, and four or five inches wide, capable of extension to 
twice this length or more“. In 30 of these alcoholic specimens the 
introvert is extended and averages 1,573 cm long, or when added 
to the above body length, is about !/;, of the total length. 
Dorso-ventral diameter. Mean 4,066 + 0,178. Standard 
deviation 2,063 + 0,125. Coefficient of variability 50,737 + 3,098. 
Range 1—8,8. 
Color. — Specimens in alcohol are liverbrown to vinaceous- 
einnamon, darker dorsally, and often nearly white ventrally. In 
some cases the tint is very dark. The young are lighter and more 
uniform in color. 
As is generally true when specimens are kept in alcohol cer- 
tain colors greatly fade (cf. EnwAsps, 1908). 
For living individuals Fagrıcıus, 1780, notes the color as 
greenish brown. Darverz, 1851, describes them as varying from 
