40 HOLOTHURIOIDEA. 
Attains a large size. Podia not confined to ambulacra. Body a 
more or less swollen sac ; podia retractile, sometimes in four rows 
in ambulacra near middle of body ; not many interambulacra podia ; 
the arrangement of the podia varies a good deal with age. Skin 
soft and smooth. 
Deposits very variable both in form and in the extent to which 
they are developed; often almost or quite absent in large examples. 
Colour ordinarily purplish or dark slate, the podia lighter, as is 
sometimes the ventral surface. Occasionally the whole creature is 
of a much lighter hue. 
May be as much as a foot long, and four or five inches wide, 
capable of extension to twice this length or more. 
Distribution. Circumpolar, extending southwards to Britain, 
Florida Reef, and California. 3-220 fms. 
a. Off Faeroe Islands, 70 fms. R. K. Burt, Esq. 
6. Orkneys. 
c-k. West coast of Scotland. John Murray, Esq. 
l-m. Montrose. W. Duncan, Esq. 
n. Plymouth. 
7. Cucumaria fucicola. 
Holothuria fucicola, Forbes § Goodsir, Atheneum, no. 618 (1889), 
p- 647; Norman, Rep. Brit. Assoc. 1868 (1869), p.316; Ljungman, 
dif. Vet.-Ak. Férh. 1879, no. 9, p. 127. 
I have not seen this species, which most authors have united 
with C. frondosa. Mr, Norman, however, noted the following 
points of difference. He says :— 
“ Cucumaria fucicola (Forbes & Goodsir). 
“The type-specimens were found not uncommonly ‘in Bressay 
Sound, Shetland, in 7 fathoms water, adhering to the stems of 
Laminarie,’ and thus in the same locality with C. frondosa. Von 
Diiben and Koren ((fversigt af Skandinav. Echinod. p. 294) 
referred this species to the young of C. frondosa, and their 
synonymy has been copied by all subsequent writers without 
inquiry. But the young of C. frondosa is like the adult, in that 
‘corpus, collum et pedum latera teguntur granulis calcareis, irregu- 
laribus, difformibus, nwaqguam perforatis, which is not the case with 
C. fucicola. 
“Specimens of this species, procured by myself in the typical 
locality, have the skin supplied with calcareous plates, which are 
very irregular in form and size, but when fully developed are nearly 
round, rather longer, however, than broad, and perforated with as 
many as 30-40 holes. The sides of the feet are likewise furnished 
with the irregular-shaped, elongated, perforated plates common in 
this position in the different species of the genus; but these fect- 
spicules I have also observed sparingly present in the young of C. 
frondosa, though in the passage above quoted Diiben and Koren 
deny their existence.” 
