Invertebrate Fauna of St. Andrews, 183 



slightly curved, about six times as long as body ; at distal 

 end about half the greatest width of body when fully ex- 

 tended (as in fig. 2) , tapering gradually towards the base. 



Body yellowish brown by transmitted light, subject to 

 considerable variations of shape (see figs. 2, 3, and 4). Pre- 

 hensile tentacles about as long as body, confined to apical 

 region, and showing a spiral structure internally under a 

 high power. 



Length of tube in largest specimens about 1 millim. 



Hah. On Caliyus rapax. 



POLYCH^TA. 



PoIygordiuSj sp. 



The larv^ of a species of Polygordlus occurred in the 

 surface-nets on August 19 and October 23 and 25, 1890. 

 Several were observed to undergo their final metamorphosis 

 after a few days' life in the laboratory. Its appearance in 

 these waters is somewhat surprising. 



Nemertea. 



A Filidxum larva was taken at the surface on October 13, 

 1890. It measured "71 millim. in greatest length, tiie height 

 without fllagellum being about the same. The tlagelluni con- 

 sisted of a bunch of line vibratile filaments, which usually 

 adhered so closely together as to have the appearance of a 

 single tapering appendage. The ventral margins in life 

 showed a beautiful arrangement of reddish-brown ])igment at 

 the bases of the cilia. The prostomial disks were a pale 

 yellow colour, and the stomach was filled with a brownish 

 mass interspersed with black dots. 



PI. XL figs. 5 and 6 represent the larva in lateral and 

 anterior views. 



Professor M'Intosh informs me that no Nemertean known 

 to undergo a Pilidium stage has been recorded from the 

 adjacent waters. 



Hydroida. 



Euphysa aurata (Forbes), the gonozooid of Corymorpha 

 nana (Hincks), was taken at the surface in the beginning of 

 August 1890. A species of Corymorpha is known to inhabit 

 the bay, but recent attempts to dredge it have not proved 

 successful. This gonozooid does not seem to have been met 

 with here before. 



