1903.] 



MARINE FAUNA OF ZANZIBAR. 



141 



a ligliter-coloured, bent, simply bluntly pointed acicular seta, 

 in tiie posterior. 



The setas are thus exactly like those of M. macintoshi except in 

 the greater size of the combs and the lai'gev number of the 

 aciculfe. 



The dorsal and ventral cii-ri are veiy short, and the latter 

 are also thick. 



Text-fig. 13. 



Marpliysa simplex, sp. nov. 15th foot, X 45. 



The gill-region extends over practically the whole body, the 

 first thirty segments alone being without them. The gills increase 

 rapidly in size, the largest having four or five filaments arranged 

 comb fashion and long enough to be made nearly to meet over 

 the back. In the smaller complete specimen gills of four filaments 

 are found only near the beginning of the gill-region ; the remaining 

 segments bearing gills of equal length but of thi-ee filaments 

 or, more posteriorly, only two, 



Maephysa furcellata, sp. nov. (Plate XV. figs. 13, 14.) 

 The head and first 120 segments of one specimen were coUected 

 between tide-marks near the town of Zanzibar, and the whole of 

 a second was dredged from 15 fathoms in Zanzibar Channel, the 

 bottom being mud. The former measures 4 cms. in length and 

 4 mm. in breadth, the latter 12 cms. by 4 mm. in the anterior 

 third, after which the breadth decreases to 3 mm. Only the first 

 few segments are round, the rest of the body being very flat 



