NOTES ON APHROCALUSTES BEATRIX GRAY. 



U7 



dermalia present exhibited a fairly plumose appearance in the distal parts 

 of their distal rays (up to 150/z long ; breadth of the plumose parts up to 

 24/j. ; longest lateral spine up to 16/i). — To sum up: The dermalia in 

 A. bcatrix orientalis consist largely of pentactins, with admixture, in vari- 

 able proportions, of hexactins in which the distal ray may be spineless and 

 simply peg-like, or spined and subpiumose, but is rarely quite plumose. 

 The said distal ray seems not to exceed 1S5/Z in length, generally standing 

 very considerably under that length. 



Somewhat a reverse of the above rule as regards the dermalia seems 

 to obtain in specimens from other parts of the world. For the dermalia of 

 these only hexactins were given by authors, indicating either absence or 

 only insignificant presence of any other, but particularly pentactine, form 

 amongst them ; and the distal ray of those hexactine dermalia has always 

 been described to be " feather-like," " fir-tree-like " or " poplar-like." 

 Thus, the Atlantic form ("A. bocagei ") of the species is known to have 

 unequivocally feather-like or fir-tree-like distal rays to dermal hexactins 

 (Carter '73, p. 450, pl. XV. fig. 9. — F. E. Schulze '87, p. 315, pl. LXXXIV. 

 fig. S). My own observations on a sample, kindly presented to me by Prof- 

 essor F. E. Schulze, from the Mid- Atlantic specimen which was obtained 

 by the " Challenger " (Stat. 344, off Ascension Island) and which was 

 identified by him as A. bocagei Wright, have shown that the dermalia in 

 that speeimen are predominantly or nearly exclusively well-developed 

 pinular hexactins, as were indeed given to be by him in the Challenger Re- 

 port. I have found the plumose distal ray to be 182 — 231/i long and up 

 to 40/i broad ; the lateral spines up to 28/^ long ; tangential rays on an 

 average 133/^ long and the proximal ray always somewhat shorter. — In the 

 type specimen of A. beatrix from Malacca the dermalia were described by 

 F. E. Schulze ('87, p. 312) to be hexactins " in which the distal ray bears 

 numerous narrow, curved, fir-tree-like, lateral prickles." — For the Bay of 

 Bengal specimens, collected by the " Investigator " and reported on by F. 

 E. Schulze ('02) as A. beatrix Gray, the author describes the dermal 

 hexactins in essentially the same strain, comparing the appearance of their 



