6o8 



Memoirs of the Indian Museum. 



a 



[Vol,. V, 



upper surface lie two small but distinct black eyes. No individual had the proboscis 

 extruded, and so far as could be ascertained by dissection there are 20-22 rows of 



papillae, 4 in each row. There is no spe- 

 cially large one in the mid-dorsal line, but 

 in the two median rows the anterior 

 papilla is a little in front of the other rows, 

 although only of the same size. This 

 point needs to be verified with better 

 material than was available. 



The ist foot (figs, ha, HB, and text- 

 fig. 11a) projects obliquely or directly to 

 the front, and does not attain the ante- 

 rior border of the head. It has well- 

 marked dorsal and ventral divisions, with 

 spines, but the lamellae are minute and 

 the branchiae are absent. On the posteri- 

 or face of each division there is a small 

 cirrus. The dorsal division is conical. 

 Above the spine there is a group of long 

 slender capillary setae, with smooth or 

 minutely serrated flattened blades. Below 

 the spine is a group of earner ated setae. 

 The ventral division is truncated at the tip. 

 The spine pierces a conical papilla, which is completely surrounded by the setiger- 

 ous fillet or lamella. Emerging between the papilla and the fillet is a ring of long 

 smooth capillary setae. No camerated setae are present in the ventral divi- 

 sion. 



The peculiar nature of the ist foot may perhaps be explained by regarding it 

 as composed of two imperfect feet. If the text-fig. 11a is turned round till the 

 cirri are ventral in position, the resemblance of each division to a single division of 

 a typical foot (text-fig. no) will be at once apparent. The ventral division, which 

 does in fact lie somewhat in front of the dorsal division, would represent the ist 

 foot, armed only with capillary setae, whilst the dorsal division would be the 2nd 

 foot, with an anterior row of camerated setae and a posterior row of capillary setae. 

 The two cirri would correspond to the ventral cirri. The papillae at the posterior 

 dorsal angles of the head may be the reduced dorsal divisions of the 2nd pair of 

 feet. On this hypothesis the two anterior feet would be represented only by the 

 ventral division of the typical foot, as in Nereis. 



In the 2nd foot (fig. 11C) the dorsal and ventral divisions are widely separated 

 from each other, and the various lamellae of the normal foot are present, though 

 still very small. There is a small ventral cirrus, and camerated setae are present 

 in both divisions. At the ventral side of the dorsal division there is a small lobe 

 (fig. ne, a), which appears to be the rudiment of the branchia. 



Text-fig. ii. — Parapodial diagrams of Nephthys 

 polybranchia, sp. nov. 



a. ist foot ; b. 10th foot. 

 • = slender capillary setae ; x = camerated setae. 



There is a minute posterior lamella. 



