98 PKOF. A. DENDY AND ME. E. HINDLE : ADDITIONS TO 



The form o£ the calcareous ring appears to be identical with that o£ 

 Stichopus mollis. 



There are twenty tentacular ampullfe ; a large Polian vesicle situated 

 ventrallj, and a madreporic canal dorsally. 



The other contents o£ the body-cavity have been ejected ; therefore we are 

 unable to add any further observations on the anatomy. 



HoLOTHURiA DIFFICILIS, Semper. (Plate 13. figs. 19 a-19 c.) 



1868. Holotliuria difficilis, Semper, Holothurieii, p. 92. 



1880. MuUeria ^Jai-vula, Haacke, iu Mobiiis, Meeresfaiina d. Inseln Mauritius u. d. 



Seychellen, p. 46. 

 1883. Holotliuria difficilis, Ludwig, Bar. Oberli. Ges. f. Nat.- u. Heilliunde, vol. xxii. 



p. 173. 

 1885. Holothuria difficilis, Lampert, Die Seewalzen, p. 68. 

 1898. Holothuria difficilis, Bedford, Proc. Zool. Soc. 1898, p. 838. 

 1901. Holothuria difficilis, Sluter, Holothurians of the ' Siboga ' Expedition, p. 10. 



Three specimens of this Holothurian w^ere obtained by Mr. R. M. Laing 

 off Norfolk Island. 



The largest is 3'65 cms. in length and 1*4 cms. in greatest width. All the 

 examples are dark brown in colour, but are somewdiat lighter on tlie ventral 

 surface than on the dorsal. 



The tube-feet are almost restricted to the ventral surface, where they are 

 very numerous. 



The internal anatomy presents no peculiar features, but it is interesting 

 to note that, although the specimens have been in spirit for at least ten 

 years, the Cuvierian organs have not lost the adhesiveness and elasticity 

 characteristic of them in the fresh condition — a fact which was noticed by 

 Semper in the specimens that he examined. 



Three kinds of spicules are found in the integument : — 



(i) Tables, resembling those of S. mollis, consisting of a base with four 

 columns supporting a spire, and two cross-bars uniting these 

 columns (PL 13. fig. 19 c). 

 (ii) Biscuit-shaped spicules, which are oval plates usually with six 

 perforations arranged in two rows of three each, but there is 

 considerable variation in the number of these perforations, as 

 shown in fis;. 19 h. 

 (iii) Irregular perforated plates occurring in the tube-feet (fig. 19 a). 



CUCUMARIA ALBA, HuttOJl, Sp. 



1872. Chirodota (?) alba, Hutton, Cat. Ecliinoderm. N.Z. p. 17. 

 1879. Eehinocucumis alba, Hutton, Trans. N.Z. Inst. vol. xi. p. 307. 



1885. JEchinocucumis alba, Lampert, Die Seewalzen, p. 167. 



1886. Echinocucmnis (?) alba, Th^el, Chall. Reports, vol. xiv. p. 119. 



1897. Colochirus alba, Dendy, Journ. Linn. Soc, Zool. vol. xxvi. p. 35. 



1898. Cucmnaria alba, Ludwig, Hamburger Magalhaeu. Sammeireise, Holotburien, p. 29 



