KEPOKT ON THE ASTEROIDEA. 1 5 



The madreporiform body is rather small, oval or subciroular in outline, and is placjd 

 rather nearer the odd supero-marginal plate than midway between it and the centre of the 

 disk. Its surface is usually level with the surrounding area, and is marked with numerous 

 fine sti'iation furrows which have the general appearance of radiating from the centre 

 outwards. Several long and prominent spinelets surround the margin, and one larger 

 than the rest stands at the adcentral side. 



The papulae are comparatively large and numerous, and occupy an area at the base of 

 the rays which may stretch as far as the sixth or eighth supero-marginal plate, though 

 seldom more than stragglers occur beyond the fifth even in large specimens : the papulse 

 also extend upon the disk, but are absent from the central region and along the median 

 interradial lines. 



There is a small genital aperture situated on each side of the odd supero-marginal 

 plate, opposite the first paired supero-marginal plate, and opening on the abactinal surface 

 close to its margin. The foramen is oval or subreniform, and is guarded by a simple 

 papilliform spinelet, attached on the adcentral margin, and directed over the aperture 

 outwards and consequently towards the marginal plate. 



Colour in alcohol, a bleached greyish white. 



Individual Variation. — So far as I am able to judge from the material at my disposal, 

 this species appears very constant in general character. The following particulars seem to 

 be noteworthy. In one example the disk is relatively large, the radial measurements 

 being R = 60 mm. ; r = 9 mm. It may be noticed also that in some cases one of the two 

 large spinelets on the actinal surface of the adambulacral plates is either much reduced in 

 size or may be absent altogether. One example presents a very interesting modification 

 in the number and disposition of the large spiracle-formed pedicellarian apparatus on the 

 actinal surface, these not being confined to the interradial area only, but three or four are 

 distributed along the ray, standing between adjacent infero-rnarginal plates ; on one side 

 of a ray four are present as well as the normal interradial ones, and the outermost one 

 observed stands between the eighth and ninth infero-marginal plates. 



Locality. — Station 343. Off the Island of Ascension. March 27, 1876. Lat. 8 o ,3'0"S., 

 long. 14° 27' 0" W. Depth 425 fathoms. Volcanic sand. Bottom temperature 40° *3 

 Fahr. ; surface temperature 80°'8 Fahr. 



Remarks. — This extremely elegant form is at once distinguished from all the other 

 species of Pararchaster by its delicately attenuate and flexible rays, and by its remark- 

 ably spinous character — the number and delicacy of the spinelets on the infero-marginal 

 and abactinal plates forming a special and conspicuous feature. 



4. Pararchaster pedicifer, n. sp. (PL I. figs. 3 and 4 ; PL IV. figs. 3 and 4). 



Eays five. R = 165-168 mm. ; r = 15 "5 mm. R = 11 r. Breadth of a ray near the 

 base, 14 mm. 



