150 HOLOTHURIIDAE. 
are fairly distinct. “As a rule the distinction between the dorsal and ventral 
surfaces is very marked but this is not always the case. The specimens were 
taken at Taboquilla and Perico Islands, Panama, in October, 1904. 
Holothuria marenzelleri. 
Lupwic, 1883. Ber. d. oberh. Ges. f. Naturk., 22, p. 167. 
\ single specimen was taken at Chatham Island, in the Galapagos, in Janu- 
ary 1905. It measures 100 mm. in length by 35-40 mm, in diameter. The 
species has been recorded previously from the Galapagos Islands, although 
it was originally described from the East Indies. 
Holothuria monocaria. 
Lesson, 1830. Cent. Zool., p. 225. 
The specimens which I refer (though not without hesitation) to this com- 
mon species are quite young, one about 40 mm., the other only 11 mm. long. 
The larger is nearly white and is possibly from Tahiti but nothing is certain 
as to the locality beyond the fact that the specimen was collected by the 1899- 
1900 expedition. There are very few buttons in the skin and the tables show 
considerable diversity of form. The smaller specimen is also nearly white. 
It was taken October 12, 1899, at Fakarava, Paumotu Islands. The tables 
are well formed but diversified with eight to thirteen marginal holes in the disk. 
There are apparently no buttons in the skin. If these specimens really are 
monocaria it would seem to be probable that tables arise some time before 
buttons and that the buttons only gradually become so numerous as to form 
the layer present in adults. But of course, only a series of indubitable growth- 
stages can determine whether this is the case. 
Holothuria pardalis. 
SELENKA, 1867. Zeits. f. w. Zool., 17, p. 336. 
A single specimen taken October 20, 1899 at Makemo, Paumotu Islands, 
seems to belong to this species but the condition is poor and the calcareous 
particles are so corroded that it is impossible to be sure of the identification. 
Holothuria scabra. 
JAEGER, 1833. De Holothuriis, p. 23. 
A single specimen of moderate size was taken at Guam, Ladrone Islands, 
February 27, 1900. 
