EEPOKT ON THE ASTEROIDEA. 291 



The terminal plate is very small and rounded outwardly. 



Young Phase. — A small example from Christmas Harbour, Kerguelen, measuring 

 R=20 mm., r=7'5 mm., presents all the characters of the adult in a remarkable degree. 

 The same low truncate uniform granules, forming the same level surface, both on the 

 actinal and abactinal areas. There is not the slightest hesitation in saying that this 

 example is the young of the species uuder notice. Its difference from the young of 

 Gnathaster meridionalis of the same size is very marked and striking. There are nine- 

 teen supero-marginal plates counting from the median interradial line to the extremity. 

 There are not more than four to seven granules in the paxillse. The armature of the 

 adambulacral plates is of the same character as in the adult. The vitreous spine-like 

 prolongation of the united mouth-plates is well developed. A single pseudo-pedicellaria, 

 conical and pointed, is present on the innermost plate in the interradial area. The 

 odd marginal plate is small in the superior series, but that in the inferior series is 

 relatively larger than in the adult, here re-entering the margin. 



There is also a young example dredged near Marion Island, in which the rays are slightly 

 narrower at the base, and though equally long are rather less attenuate outwardly, and the 

 abactinal surface is somewhat less full and baggy. In these slight differences this young 

 form resembles the adult specimens from the neighbourhood of Heard Island more closely 

 than it does those from Kerguelen. This example is figured on Plate XIX. 



Variations. — The principal variation that I have noted is in some large examples 

 from Christmas Harbour, Kerguelen, in which the breadth of the ray at the base is 

 greater, and gives a more triangular form to the ray. The flexible and almost baggy 

 character of the abactinal surface is also more noticeable, from which I infer, as well as 

 from a less collapsed example, that the form was tolerably thick and puffy over the disk 

 when alive. The actinal area is decidedly convex ; and when the whole starfish is 

 viewed in profile, the narrow double band of marginal plates appears as a slightly nipped- 

 together ridge midway between the abactinal and actinal convexities. It is interesting 

 to note that in one of these examples the primary interradial plates are distinctly 

 observable on the disk. They are small, oval, slightly convex plates, situated at about 

 the same distance from the centre as the large crescentiform plate on the adcentral 

 side of the madreporiform body, but are, however, of much smaller size. In one of 

 these examples I notice a tendency to lateral compression and truncation at the tip of 

 the innermost furrow spines in the adambulacral armature ; but not in others : the 

 circumstance is therefore only noted as a point affected by variation. 



Colour in alcohol, a bleached dirty ashy or greyish white. 



Localities.— Station 145. Off Marion Island. December 26, 1873. Depth 50 fathoms. 



Station 149h. Off Cumberland Bay, Kerguelen Island. January 29, 1874. Depth 

 127 fathoms. Bottom deposit a greenish volcanic mud. 



Station 150. Between Kerguelen Island and Heard Island. February 2, 1874. Lat. 



