SEGMENTATION OP CERTAIN POLYCH^TES. 



531 



The spiral is therefore a right-handed one as viewed from 

 the dorsal surface. This will be understood by reference to 

 fig. 1 (PI. XLII), although in the specimen there represented 

 the spiral is half a turn longer. 



In another collection of Polychaetes from shallow water off 

 Ramesvaram Island in the Gulf of Mauaar, sent to me for 

 identification by Mr. Thurston, of the Madras Central Museum, 

 there are seventeen specimens of Amphinome (all belonging to 

 the sub-genus Eurythoe), of which two have intercalated half- 

 segments, and six (one of them the same as one of the two 

 with intercalated half-segments) have spirals of varying lengths. 

 The position of both these variations with regard to the whole 

 animal in the different specimens will be seen from the fol- 

 lowing table : 



the xth parapodium on the side of the body mentioned (or the a:th parap. — 2 

 in the case of the Eunicidge). 



^ The description of the spiral given in this column applies when the 

 animal is viewed from the dorsal surface with its anterior end in front. 



5 PI. XLII, fig. 1. 



» PI. XLII, fig. 2. 



