142 Mr. P. 8. Abraliam on some Oenera 



from a common base in front of, and partially sheathing, the 

 broad, tubular, fimbriate anus. The central plume is distinct 

 and the longest ; after giving off two long lateral branches, 

 at about half its length, it becomes bifid. The other plumes, 

 about ten each side, arise from a lateral arm of the base, pro- 

 duced and incurved posteriorly ; they diminish in size and 

 become more crowded backwards, and many of them divide 

 once or twice dichotomously ; they are all pinnate, with deli- 

 cate, overlapping, lateral laminse. Together with the anus, 

 they are retractile wathin an anteriorly lipped circular cavity, 

 which is situated a little behind the central point of the body. 

 The mouth is large and, when contracted, a longitudinal fissure, 

 opening rather downwards. There is a semicircular transverse 

 furrow above, and, at each side, near the foot a deep rounded 

 pit. The pedal surface is a long and linear deep groove, ex- 

 tending to the end of the tail ; the lateral edges are crenu- 

 late and can be approximated together across the middle line, 

 but there is no free border ; anteriorly it is rounded, with the 

 margin inwardly fleshy and lobulate. The general colour of 

 the animal is a brownish cream, with small, scattered milky 

 spots and faint, reticulating, ocellated markings ; the stalks of 

 the branchiae are sparingly spotted or lineated with opaque 

 white. 



Dimensions (in spirit) : length Q6 millims., breadth 14, 

 height 18, length of the tail 29. 



Hob. unknown. 



C tenue differs from C. trilohatum and C. graciUimum in 

 wanting the latero-dorsal lobation and in having a compara- 

 tively shorter tail. 



Ceratosoma hrevicaudatum^ sp. nov. PI. VII. fig. 6. 



C. oblocgum, levatum, sublaeve, cerviuum, ocellis albis tubercularibus 

 sparse maculatum ; Cauda brevi ; dorso vix lobato ; tumore post- 

 brancbiali parvo, rotuudato, supra piano ; tentaculis dorsahbus 

 obtusis. rotundatis, laminatis, intra vaginas breves retractilibus ; 

 brancbiis brevibus, gracilibus, ramosis, ex sex radicibus orientibus, 

 ante anum semicirculariter positis, et in foramen commune re- 

 tractilibus. 



The body is elongate, but compact and raised. The dorsal 

 surface is oblong, indistinctly trilobed in outline, curving up- 

 wards from above the mouth, the highest part being in front 

 of the branchiffi. Behind the latter the outline abruptly acu- 

 minates and passes into a small, rounded, nodular protuberance, 

 flattened above. Beneath this the body- wall falls nearly per- 

 pendicularly, and then ends in a short, laterally compressed, 

 conical tail. The dorsal tentacles are clavate, the upper half 

 flatly rounded at the apex, being bent back and bearing about 



