636 Memoirs of the Indian Museum. [Vox,. V, 



Polydora (Carazzia) kempi, sp. nov. 

 (Plate XXVIII, figs. 20A-J.) 



Five specimens of this species were collected from a canal near Calcutta. Un- 

 fortunately the specimens are all incomplete, and nothing is known of the posterior 

 end. The longest fragment is 65 mm. long, composed of 27 setigerous segments. 

 The body is of the usual shape, the anterior region being flattened dorsally, some- 

 what rounded ventrally. Near the 17th segment the body becomes round in section. 

 The anterior segments are short, but gradually elongate, till at the 20th they are 

 nearly as long as broad. 



The anterior segments have each a single transverse line of black spots on the 

 dorsum, but the line is sometimes reduced to two median spots. 



The head (fig. 20A) is rather small and broad. It bears in front two short but 

 distinct anterior lobes. There are four black eyes, the two posterior being small and 

 round, whilst the anterior pair, which are more widely separated than the others, are 

 crescentic. The posterior margin of the head is rounded, and there is no caruncular 

 prolongation, but instead there is a large erect occipital tentacle, lying between the 

 bases of the tentacular cirri. The latter organs are relatively large. 



The ist foot (fig. 20C) consists of a stumpy round dorsal papilla, without dorsal 

 setae. The ventral setigerous lobe is vertically elongate, with a row of slender capil- 

 lary setae, which have only slightly flattened blades. 



The 2nd foot has a fairly large rounded dorsal lamella lying behind the dorsal 

 setae. The dorsal setigerous lobe is conical, and the setae are long and slender, with 

 only slight indications of a wing. The ventral setae are shorter and wider than the 

 dorsal, with narrow wings. 



In the 3rd foot the lower dorsal setae are wider than those in the 2nd foot, and 

 have wings. The ventral setae have increased in size, and are very distinctly flattened, 

 with slender tips. These changes are much more marked in the 4th foot (fig. 20D), 

 especially in the dorsal division. The upper dorsal setae remain long and slender, 

 with very narrowly winged tips, but there is a gradual transition to the lower ones 

 (fig. 20G), which are short and boldly curved, with widely winged blades. The ventral 

 setae, in two rows, are all lance-shaped (fig. 20H), those at the lower border being very 

 slender. The lower edge of the dorsal bundle curves backwards a little, as in 

 P. antennata, Clap. (Mesnil, 1896, p. 228), and this tendency is much more obvious in 

 the next segment. 



The 5th foot (fig. 20E) seems to be less modified than that of any other 

 species of Polydora, and is very similar in structure to the 4th foot, as may be seen 

 from a comparison of figs. 20D and 20E. Mesnil (1896, p. 235) on the contrary, ex- 

 presses the view that in P. polybranchia, Haswell, and P. (Carazzia) antennata, Op., 

 the 5th segment has undergone greater modification than in any other species of 

 Polydora. This opinion is apparently based on the presence, in these two species, of 

 two kinds of modified setae in the 5th segment. If the 4th and 5th feet of P. kempi 

 (a species very closely related to P. antennata) are compared, it will be apparent that 



