BY E. J. GODDARD. 491 



tentacles are about 1 mm. in length, and 001 mm. in diameter, 

 these very slender structures rendering a graceful appearance to 

 the animal. The lumen is about equal in diameter to the large 

 cells composing the wall. These cells are square in shape, as 

 seen in transverse section; and contain a large, deeply staining, 

 centrally placed nucleus, about 5 or 6 of the cells encircling the 

 lumen. They bear a strong resemblance to those lining the 

 ■epistome. When the tentacles are retracted, it is seen in section 

 that the lophophore is no longer elliptical in shape, but has been 

 invaginated on the anal side so that two horns of it project on 

 either side of the epistome; and this gives, in section, an appear- 

 ance similar to that which exists among other members of the 

 Phylactoloimata, e.g., Lojyhoinis, Cristatella, etc. This point has, 

 perhaps, some little interest in this respect, inasmuch as Frederi- 

 ■cella is unique among the members of the Phylactolcemata in 

 having a lophophore which is circular or elliptical, and not horse- 

 shoe-shaped, and bridges over the gap in this direction between 

 Fredericella and other genera, the folding, which one might on 

 other grounds treat as being of no value, occurring in such a way 

 ■that it agrees exactly as regards its detailed direction with the 

 other genera. In counting the tentacles, use was made of trans- 

 verse sections, so that no error could be made in this reckoning 

 which is very difficult and unreliable if one used ordinary entire 

 anounts of killed specimens. The epistome is a bluntly rounded 

 tongue-like process, about 0'09 mm. in length. As seen in trans- 

 verse section, it is oblongate-elliptical, with a slight concavity on 

 the anal side, giving it a faint reniform contour. These sections 

 measure 0*07 mm. in a line at right angles to the axis joining 

 mouth and anus, and 0*016 mm. along that axis itself. The 

 organ is thus seen to be flap-like in nature Its wall consists of 

 large columnar or squarish cells, with centrally situated nuclei, 

 the limits of which, like the cells of the tentacles, which they 

 much resemble, being readily made out. These cells constitute 

 the wall in its entirety, no muscular layers, etc., being visible. 



The oesophagus is about O*.'^ mm. in length, and varies much in 

 shape according to the condition of the polypide. In good 



