REPORT ON THE ASTEROIDEA. 145 
the end of the ray the papilla are turned back and directed slightly over the furrow, 
instead of being closed down upon the surface of the plate, and the pit is probably aborted. 
The mouth-plates form a rather broad mouth-angle, presenting a well-developed keel 
along the median line of junction, more or less imperfectly closed along the suture and 
widely open at the aboral extremity. A single, short, conical, sharply pointed mouth- 
spine to each mouth-angle stands at the innermost point, and in the median line. Two 
large segmental papillae occupy nearly the whole of the lateral portion of each mouth- 
plate ; they stand close together, touching one another, and the aboral one is the larger 
of the two. (See Pl. XXVII. fig. 6.) 
The actinal interradial areas are small, and the squamous intermediate plates are 
comparatively few in number, these being rather large in the immediate angle, though 
very narrow and elongate near the margin. 
Colour in alcohol, greyish white, excepting the abactinal membrane, which is 
bluish grey. 
Locality.—Station 298. Off the western coast of South America, between Valparaiso 
and the Island of Juan Fernandez. November 17, 1875. Lat. 34° 7’ 0” S., long. 73° 
56’ 0” W. Depth 2225 fathoms. Blue mud. Bottom temperature 35°°6 Fahr. ; surface 
temperature 59°:0 Fahr. 
Remarks.—This species is distinguished from Porcellanaster crassus, the only other 
form having segmental pits and papillw, by its short and delicate rays, by its com- 
paratively unarmed supero-marginal plates, and by the limitation of the spinelets 
on the abactinal surface to definite areas. 
6. Porcellanaster eremicus,' n. sp. 
Since my preliminary notices on the species of Porcellanaster® were written I have 
received a very young form which had been found in a bottle of other material that 
had been sent to America. It is without doubt a Porcellanaster, and at a very early stage 
of growth. The measurements are R=6°5 mm.; r=3'25 mm. The form appears 
to be nearly related to Porcellanaster cxruleus, and the most striking, if not the only 
real specific difference that I can detect at this stage is that the rays are longer, more 
attenuate, and thinner throughout. 
At such an obviously early phase it would serve no good end to endeavour to draw 
up a specific diagnosis which would enable the adult stages to be recognised when found. 
I shall therefore limit myself to some remarks on the interesting features presented 
by this example. As I feel convinced, however, from the characters shown by the young 
form, and from the isolation of the habitat, that the species is distinct, I have ventured 
to assign a name to it. This course will also facilitate reference. 
1 eonusxds, accustomed to solitude. 
2 Journ. Linn. Soc. Lond. (Zool.), 1883, vol. xvii. p. 214. 
(ZOOL, CHALL, EXP.—PART LI.—1887.) 19 
