356 Messrs. Brady and Robertson on Dredging 



" Ophianoplus annulosus. 

 " Disco supra fusco annulis albis ; spinis brachiorum 12. 



" This Ophiuridan, of which I found a single example at 

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

 new genus, allied to Ophiocoma, 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 Ophiopsila, 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-papillae 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 

 papillae 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-papillae of the Am- 

 pMurcBj with which this mouth-organ of Ophianoplus entirely 

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

 presents a number of rounded tooth -processes, as in Ophiocoma, 

 which form three or four irregular rows. The masticatory 

 organs, which are broader than those of Ophiocoma, and formed 

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

 those of Ophiopholis scolopendrica and Ophiothrix fragilis, 

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

 and from the last in having mouth-papillae. 



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

 the disk, and differ from those of other Ophiuridae 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 are 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 

 plates are much elevated, and have a prominent encircling 



