PART 5 A MONOGRAPH OP THE EXISTING CRLNOIDS 219 



priate situations, as otherwise they would be found iiidisciiiainatcly on sucli objects 

 as fuci, shells, or stones. 



Off Ireland's Eye the pentacrinoids are always found growing on Delesseria san- 

 guinea (Forbes, 1841, on the authority of Messrs. R. Ball and Wni. Thompson). In 

 the Bay of Cork they are found attached to the various species of Sertularia and Flus- 

 tracea, which occur in the deeper parts of the harbor of Queenstown, in 13 to 18 meters 

 (J. V. Thompson, 1827). 



In Lamlash Bay, Professor Carpenter (1866) never found them affixed to anything 

 else than the fronds of Laminaria, to which the adults habitually cling, or to Polyzoa 

 or Spirorbes gi-owing on these. Herdman (1904) also noted that here the young occur 

 on Laminana, and on Fu^us, and Grieve (1868) found them on Laminaria off the Little 

 Cumbrae. 



Sii- Wyville Thomson, however, found clusters of pentacrinoids attached to the 

 inner surface of a dead valve of Alodiola modiolus. 



At Port Erin the pentacrinoids attach themselves to seaweeds (Herdman, 1886), 

 chiefly Laminaria fronds (Herdman, 1881). But at Ilfracombe, where Laminaria is 

 much less abmidant, and the polyzoan Cellaria grows in great luxuriance in the habitat 

 of Antedon, they are found adherent to its stony polyzoary (W. B. Carpenter, 1866). 



Mr. Peach (1864) frequently met with the pentacrinoids when he lived in Cornwall. 

 In 1844, as he found on referring to his diary, he noticed many moored on the stones 

 used to sink the crab-pots, and also on the rods of which the pots were made. 



At Torbay, Mr. Hughes (1873) found them attached to a Laminaria frond, while 

 Major Lang (1877) found them in abundance on seaweeds and zoophytes, principally 

 on Bugula and Cellaria; he says that there were at least 70 on a zoophyte 2 inches long. 



In the Salcombe estuary Mr. Stebbing (1877) found them on eel-grass {Zostera 

 maiina) . 



At Plymouth the pentacrinoids occur chiefly on Cellaria (E. W. L. Holt, in Pace, 

 1904). 



At Roscoff pentacrinoids seem to choose a greater variety of objects for attach- 

 ment than anywhere in the British Isles, for Perrier (1873) found them growing either 

 on the pinnules of the mother, or on various submerged objects such as Laminaria 

 and other algae, the polyps of polyzoans or of hydroids, annelid tubes, etc. 



Whenever found, pentacrinoids are usually abundant. Lacaze-Duthiers (1869, 

 1870), Lang (1877), Hunt (1877) and others have especially noted this, indeed the fact 

 has been frequently remarked by many naturalists from J. V. Thompson (1827) and 

 Forbes (1841) onward. J. V. Thompson \vrote that the great abundance of comatulids 

 in the places they inhabit is not to be wondered at when we are aware how exceedingly 

 prohfic they are; thus each arm may be estimated to bear 30 fruitful ovaries, each 

 producing about 100 ova, and as there are 10 arms, this gives 30,000 as the amount of 

 ova produced by a single individual. 



Grieve (1868) mentions a Laminaria frond brought up from 9 to 18 meters off 

 Little Cumbrae being thickly covered with pentacrinoids, and W. B. Carpenter (1866) 

 states that they are generally scattered over the surfaces of these so as not to be in any 

 near proximity to each other. 



But sometimes (W. B. Carpenter, 1866) there is found a group of several pentacri- 

 noids very close together so as to present in one view all the stages in development 

 represented on plate 33, part 2. He had in his possession one sample in which more 



556-622—67 16 



