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



The actinal interradial areas are small, and confined to the interbrachial region, not 

 appearing to extend beyond the fifth or sixth infero-marginal plate counting from the 

 median interradial line ; they are occupied by small intermediate plates arranged in regular 

 columns, which bear a number of small, short, skin-covered papillae, with three or four 

 much larger than the rest in the midst, forming a massive pedicellarian apparatus ; a 

 few of the innermost plates in the large specimen have one papilla more spiniform than 

 the others, and this may either be present along with the pedicellaria or in its place. 



The anal aperture is subcentral and distinct, although there is no change in the form 

 of the paxillae in its neighbourhood. 



The madreporiform body is compound, and occupies a large circular area about 10 mm. 

 in diameter, its outer edo-e beincr not more than 2 or 3 mm. distant from the marginal 

 plates. Numerous large paxillae, much greater than any of the others on the abactinal 

 area, spring from, or at the junction of, the madreporic plates, almost entirely hiding the 

 striated surface from superficial view. This may be seen in places, however, for the 

 paxillae are not very closely placed, and here and there one is wanting. The striations 

 are seen to be very fine, numerous, and very slightly convoluted. The papillae which 

 compose these paxillae are rather more robust and distinct than those of the general 

 paxillae, having more the appearance of hemispherical granules when seen from above ; 

 and none are modified into pedicellarise. 



Colour in alcohol, a bleached yellowish white. On one of the small specimens there 

 are traces of a dark purple colour along one of the rays, but whether this is the original 

 colour of the species, or is only pigment derived by abrasion from some other organism, 

 I am unable to say. 



Locality. — Station 89. Between the Canaries and the Cape Verde Islands. July 

 23,1873. Lat. 22° 18' 0" N., long. 22° 2' 0" W. Depth 2400 fathoms. Globigerina ooze. 

 Bottom temperature 36°"6 Fahr. ; surface temperature 73°5. 



2. Lonchotaster forcipifer, n. sp. (PL XXXI. figs. 5 and 6; PI. XXXII. figs. .9 and 10). 



Pays five. E = 20 mm. ; r = 7 mm. R > 3 r. Breadth of a ray between the sixth 

 and seventh infero-marginal plates, 5 mm. 



Disk comparatively large and inflated. Pays moderately elongate, subdepressed and 

 subcarinate, narrow and tapering throughout to the extremity. Interbrachial arcs wide 

 and well rounded. Abactinal surface convex over the disk, the slight carination of the 

 rays culminating in a distinct tumidity on the inflated disk-area at a little distance from 

 the base of the ray. Actinal surface of the disk plane, but becoming rounded on the 

 outer part of the ray. Lateral walls low and more or less rounded. 



The abactinal surface of the disk and ra) 7 s is covered with very small and closely 

 packed paxillae, consisting of five to eight small, short, but comparatively robust, 

 papilliform spinelets, one of which is frequently central. The tips of these papillae are 



