2^8 THE GREAT BARRIER REEF. 



'o 



forming a single series ; slender tactile papillae developed abundantly throughout the dorsal aspect; 

 vent cj-lindrical, devoid of anal ossicles ; colour, purple black ; a dark red fluid exuding from the 

 surface of the skin when the animal is handled roughly ; oral tentacles and ventral acetabula, 

 black. Length when extended, twelve to eighteen inches. Habitat : Common on the outlying 

 reefs of the Great Barrier system. Of but little commercial value. The muscular and connec- 

 tive tissues of this species are of much less firm consistence than those of the black, red, or teat 

 varieties, and when cured the individual bodies are comparatively hollow and of light weight. 



17. Black Cotton-fish, Holothnria atra (Plate XXXIII. b). — Body in extension elongate 

 cylindrical, most slender anteriorly ; profusely papillose throughout, through the presence of 

 the thickl3'-developed, slightly protruding bases of the acetabula ; oral tentacles and ventral 

 acetabula dark brown or black. Length fifteen to eighteen inches. Emitting large quantities of 

 cotton-like Cuvierian filaments. Common on all inshore reefs; usually, when extended, having 

 a portion of the hinder region of its body retained within a crevice of the reef Of no com- 

 mercial value. 



18. Snake-like or Yellow-plumed Beche-de-mer, Holothnria coluber (Plate XXXV. a and 

 Chromo XII., Fig. 5). — Body in extension elongate cylindrical, tapering anteriorly; closely resem- 

 bling that of the last species, but the surface of the integument harsher, somewhat coriaceous ; 

 general ground colour purple-black, ventral pedicels and points of tactile acetabula orange or 

 yellow, the oral tentacula primrose-yellow. Length eighteen to twenty inches, not emitting 

 cottony Cuvierian filaments. Common on inshore reefs in company with H. atra, but more often 

 crawling freely on the surface of the reef Of little or no commercial value. 



19. Yellow Cotton-fish, Holothnria vitiensis. — Bod}' in extension elongate-ovate, depressed, 

 its surface smooth ; aperture of the vent distinctly stellate ; ground colour throughout tawny- 

 yellow ; the oral tentacles and tactile acetabula grey-brown. Length ten to fourteen inches. 

 Emitting vast masses of tenacious, cotton-like Cuvierian filaments, abundant on the level surfaces 

 of the reefs, and among the grassy (Zostcra) flats. Of no commercial use. 



20. Corrugated Beche-de-mer, Holothnria botellns. — Body in extension elongate sub- 

 cylindrical, tapering anteriorly ; thickly beset with wart-like elevations that represent the bases 

 of the tactile acetabula ; colour of the general surface of the body grey, that of the wart-like 

 papillae light yellow ; oral tentacles, ventral pedicels, and tactile acetabula light yellow. Not 

 emitting Cuvierian filaments. Common under rocks or coral boulders on the foreshore reefs. 

 Of no commercial utility. 



The descriptions of Beche-de-mer included in the foregoing list and diagnostic synopses 

 comprise all the commercially valuable species of the Great Barrier district, and also the 

 conspicuously large varieties, which are liable to be mistaken by " new-chum " explorers for 

 commercial species. In addition to these there are a considerable number of Holothuriae of 

 smaller size or possessing features which render them easily distinguishable from the edible 



