356 Messrs. Brady and Robertson on Dredging 



" Ojpliianoplus anmdosus. 

 " Disco supra fusco annulis albis ; spinis brachiorum 12. 



" This Opliiuriclanj of which I found a single example at 

 Naples, in a deptli of 40-50 fathoms, forms undoubtedly a 

 new genus, allied to OjpJii'ocoma, from which it is easily dis- 

 tinguished by its naked, non-granular disk. 



" The disk is very stout or convex, though tolerably flat 

 above, the circumference somewhat five-sided, being promi- 

 nently arched between the rays, the ventral side rather convex. 

 It is without any kind of armature whatever, being invested 

 only by a smooth integument, and without any ray -plates, by 

 which it is separated from Forbes's genus OjjJiiopstla, to which 

 it has some likeness. On the underside are ten genital fissures. 

 The mouth-plates are small, rounded, but little longer than 

 broad ; and one of them, the madrepore-plate, is a little larger 

 than the other four, circular, and surrounded by a spongy, 

 elevated, and deeply punctate border. The mouth-fissures are, 

 as in the genus Amphiura of Forbes, beset at the outer end 

 (the sides being naked) with six hard papilla?, namely : — four 

 conical and rather flattened, two on each side, of which the 

 two largest are situated on the outer side of the first ventral 

 ray-plate, and answer to the scale-shaped mouth-papillte of 

 Amphiura] the other two are a little smaller and situated 

 directly under the small tooth-processes, of which we shall 

 speak presently ; lastly, there are two very small lancet-shaped 

 papillffi placed higher up in the mouth-cavity, the points 

 of which are turned inwards towards the mouth. These last 

 correspond to the lancet-shaped mouth-papillge of the Am- 

 phhircCj with which this mouth-organ of Opliianoplus entirely 

 agrees, except that the under surface of the 'tooth-columns' 

 presents a number of rounded tooth -processes, as in OpMocoma^ 

 which form three or four irregular rows. The masticatory 

 organs, Avhich are broader than those of Opliiocoma^ and formed 

 of a kind of bristles, have in that respect some likeness to 

 those of Oplilopliolis scohjjendrica and OpMotlirix fragilis^ 

 but differ from the first in having numerous tooth-papillge, 

 and from the last in having mouth-papilla3. 



" The rays are five or six times as long as the diameter of 

 the disk, and difier from those of other ()})hiuridjB in being 

 thicker near the middle than at the base : they are nearly 

 cylindrical, very convex above and at the sides, but flat below. 

 The dorsal ray-plates arc very small, rounded, about as broad 

 as long, with a convex distal margin, the ventral plates a little 

 longer, furcate, with the distal margin hollowed out ; the side 

 ]jlates arc much elevated, and have a prominent encircling 



