86 DE. G. S. BRADY ON MTODOCOPA OBTAINED 



Cyclasteeope hendersoni, n. sp. (Plate XV. figs. 1-12.) 



Shell of the female (fiss. 1, 2) very tumid, subspherical : seen from the side broadly 

 ovate ; greatest height situated near the middle and equal to two-thirds of the length ; 

 anterior extremity somewhat narrowed in comparison with the posterior, which is 

 broad and well rounded ; the beak narrow, curved, and sharply pointed, notch very 

 narrow ; dorsal margin boldly arched, but towards the front flattened and rather steeply 

 sloping ; ventral margin evenly and gently convex. Seen from above the outline is 

 subovate, wide in the middle and but slightly tapered towards the extremities, width 

 nearly equal to the height ; lateral margins strongly convex, anterior extremity rather 

 abruptly narrowed, obtuse and slightly produced, posterior rounded. Surface of the 

 shell smooth or but very slightly punctated ; tlie anterior margin clothed with very 

 small fine hairs ; colour yellowish. Length 7 millim. Male unknown. 



Frontal tentacle (fig. 3) stout, two-jointed, the basal joint short ; apical joint twice as 

 long, subclavate, constricted at the base, and slightly also in the middle, whence it 

 tapers gradually to the extremity. Secondary branch of the antenna (fig. 4) two- 

 jointed, geniculated, basal joint bearing several marginal setae, distal joint one long 

 ringed seta. The basal joint of the mandibular foot bears a falciform masticatory 

 process the convex side of which is, towards the apex, divided into numerous very 

 irregular processes (figs. 6-8), those at the apex being slender and falcate, the others 

 broader, tooth-like, and marginally denticulated : below this series of processes the 

 margin of the organ forms a flattened laminar flange which bears several transverse 

 rows of spinules. The last pair of limbs (" vermiform feet ") take the form, usual in 

 Cypridinidse, of flexuous hollow cylinders containing in the interior a spirally coiled 

 chitinous thi'ead : the free extremity (fig. 9) has four sets — two on each side — of spine- 

 like teeth, and bears a vast number (about two hundred and fifty) of fine barbed setee 

 /■fig. 10), which spring irregularly from the margins of the segments and are of various 

 lengths, a single segment frequently having on each side three setae of difierent sizes, 

 others only one or two. 



Each caudal lamina bears eight slender curved ungues, w^hich increase progressively 

 in length from the first to the last, the first four, however, being distinctly smaller and 

 less robust than the rest (fig. 11) ; the concave margins of the ungues finely pectinated 

 with lancet-shaped spinules (fig. 12). In the intervals between the third, fourth, fifth, 

 and sixth ungues are attached small marginal setae about one-third as long as the 

 ungues themselves : the abdominal margin in front of the ungues is densely hispid. 



The eyes consist of subreniform black pigment-masses about which numerous 

 simple convex lenses are clustered in regular rows ; a delicate capsule invests the 

 whole structure, and is continued over a peduncle in which are contained muscles for 

 the movement of the eye as well as numerous nucleated (nerve ?) cells. The whole 

 organ lies loosely within the shell and has no attachment to the body of the animal 



