838 MB. F. p. BEDFOED OJf HOLOTHUBIANS [NoV. 1 5, 



Eotuma : (1) 50 mm. x 20 mm. ; (2) 64 mm. X 19 mm. ; (3) 45 mm. 

 X 18 mm. ; (4) 47 mm. X 23 mm. 



Deposits quite agree with Ludwig's later description (1883, I. c.) 

 of H. pervicax ; the tables have, as a rule, a rudimentary spire and 

 are not frequent ; in a small piece all the different forms oE 

 deposits from those typical of H. pervicax Selenka to those typical 

 of H. depressa Ludwig can easily be found, a few approaching 

 those typical of H. fuscocinerea Jaeg. {v. fig. 2 h). 



This species, like H. atra Jaeg., has been repeatedly described 

 under a new name on account of the great amount of variation 

 to which its deposits are subject. 



Like H. atra it seems to occur in two well-marked forms : var. 

 (1), first described by Semper under the name of H. fuscocinerea 

 Jaeg., and later by Ludwig as H. curiosa, in which the deposits 

 consist of sparsely distributed tables (some, according to Theel, 

 with more than one transverse beam) and somewhat irregular 

 small buttons, which become more elongated in the ambulacral 

 appendages ; and var. (2), first described by Selenka under the 

 name H.pervicax and later by Ludwig as E. depressa, which differs 

 in the fact that the buttons are not so completely formed : in 

 ai'rangement of ambulacral appendages, calcareous ring, and 

 internal anatomy, the two varieties seem to be identical ; in colour 

 they differ slightly'. I have had an opportunity of examining 

 some of Prof. Semper's original specimens, and those from Samoa 

 which he describes as varieties of H. fuscocinerea (Semper, I. c. 

 p. 250) agree in every respect with H. pervicax. 



Ludwig (1883, 1, c.) has shown that H. pervicax, H. depressa, and 

 H. mammiculata should be associated together, aud Theel (p. 221, 

 I. c.) has suggested that If. curiosa and H. fuscocinerea are identical, 

 a view in favour of which there seems to be considerable evidence. 



H. argus Jaeger (Bohedschia) seems to be closely allied to this 

 species. 



HoLOTHUKiA DiFFiciLis Semper. (Plate LII. fig. 3.) 



Holothuria difficilis C. Semper, Eeisen im Arch. Philipp. Bd. i. 

 Hoi. 18(58, p. 92, Taf. xxx. fig. 21. 



Distribution. Eecorded from Samoa, Amboina, Pulo Edam, and 

 Mauritius. 



Six specimens from Eotuma, largest 62 mm. x 20 mm., others 

 about half this size. 



The ground-colour of the smaller specimens is dark chocolate- 

 brown. 



They agree with Semper's short description and figures, to which 

 I have nothing further to add ; both the dorsal papillae and ventral 

 feet possess supporting perforated plates. Buttons, as a rule, with 

 3 pairs of holes. 



The species appears to me to be much more closely allied to 

 Actinopyga excellens aud A. parvula than to Holothuria vagahunda. 



1 V. Semper, Taf. xxvii. 



