124 THE VOYAGE OF H.M.S. CHALLENGER. 



Station 200. East of Sainboangan, Philippine Islands. October 23, 1874. 

 Lat. 6° 47' 0" N., long. 122° 28' 0" E. Depth 250 fathoms. Green mud. Surface 

 temperature S5°"5 Fahr. 



On the reefs at Kandavu, Fiji Islands. August 1874. 



Remarks. — Attention may be drawn to the occurrence of this species at 250 fathoms 

 (Station 200), for it is, so far as I am aware, the greatest depth at which Archaster typi- 

 cus has been found. I can detect no differences worthy of remark between_these examples 

 and specimens from shallow water. 



It is interesting to note that amongst this series from Station 200 there are two 

 examples which are provided here and there with short, conical, robust, stunted spinelets, 

 standing upright on the upper margin of the supero-marginal plates. These spinelets are 

 quite irregular in their occurrence. In one of the examples less than a dozen are present 

 on the whole starfish, but in the other case they are much more numerous. In this 

 example it is also to be remarked that the lateral walls of the rays are much more vertical 

 than in the other specimens from this locality, the supero-marginal plates being less 

 bevelled or arched towards the abactinal surface, with which the lateral wall consequently 

 forms a more angular junction, resembling in this respect the character of Archaster 

 angulatus. In all other respects this interesting specimen is an extremely well-marked 

 example of Archaster typicus. 



Liitken 1 has placed on record the presence of occasional spinelets on the supero- 

 marginal plates of this species, and it appeared to be of frequent occurrence in the large 

 series of examples from the Nicobar Islands studied by him. Through his kindness I had 

 the opportunity of examining a remarkably fine example from Billeton in the Natural 

 History Museum at Copenhagen, in which from four to six spinelets were present on each 

 side of a ray. In the Museum at Leyden are examples from Java and the Togean Islands 

 (N.E. of Celebes) also similarly characterised, and this form has been named in manuscript 

 by Professor C. K. Hoffmann Archaster typicus, var. multispina. The presence of these 

 spinelets on the supero-marginal plates is so very irregular and sporadic, and seems to 

 me to be unaccompanied by any other character of sufficient importance, that I fail to 

 appreciate the necessity of ranking the examples in question as a named variety. 



The normal composition of the adambulacral armature in this species is: — (1.) A 

 furrow series of three spines, the middle one much in advance of the other two, at the 

 apex of the angular projection of the plate ; (2.) on the actinal surface of the plate are 

 three spines, often flattened and truncate, forming a lineal series slightly oblique in 

 relation to the axis of the ray (on the outer part of the ray there are usually only two 2 ) ; 

 behind these are two much smaller spinelets, placed wide apart and close to the margins 



1 Videnshab. Medd. naturh. Foren. i Kj<j>benhavn, 1864 (1865), p. 136. 



2 Liitken [has remarked on the apparent discrepancy in the original diagnosis of Miiller and Troschel 

 (System der Asteriden, p. 65), in which two are stated to be the normal number. (Videnshab. Medd. naturh. 

 Foren. i Kjipbenhavn, 1864 (1865), p. 135.) 



