New Forms of the Hemichordata. 157 



external epithelial layer of the body. Internally the nephridia opened 

 in the lateral mesenteries, there being two very marked and wide 

 openings to each. These openings were composed of deeply staining 

 masses of cells, which extended up on to the transverse septum. 

 They w r ere not, as in other species, continued down on the lateral 

 mesenteries. 



Ova. — Specimen C was in all respects like in general form and 

 colour to A and B, so far as could be ascertained by microscopic 

 examination of the living animal protruding from its tube. There 

 were no eggs or embryos in the tentacles, but, on one occasion, when 

 the animal was retracted, a large number of ova were seen lining 

 the mouth of the tube, and these were held together by a gela- 

 tinous substance. The eggs were slightly yellow in colour and 

 •1 mm. in diameter. They were all in a very early stage of de- 

 velopment. Both the animal and eggs were torn off, probably 

 by a fish or other animal in the tank, only a part of the animal 

 and tube being left, so that later stages of the eggs were not 

 observed. 



IL— PHORONIS CAPENSIS, sp. n. 

 (Plate XVI., fig. 1.) 



There are no satisfactory features by which the various forms, which 

 are here included under the genus Phoronis, to which this species 

 belongs, may be separated from each other, and the description of 

 a supposed new species cannot be drawn up on very definite lines, 

 but rather with a view to affording details, some of which may 

 subsequently be found to be of systematic value. Such particulars 

 are size, form, colour, number of tentacles, tube, number and 

 development of longitudinal muscles, nerve chord, &c. 



Size, d'c. — The body of this species is neither particularly large 

 nor small. The largest specimen was not more than 1 mm. in 

 diameter at the end of the body immediately below the lophophore. 

 This might be reduced to about half this diameter when the 

 animal was fully extended from its tube. The total length of a 

 specimen removed from its tube was 21 mm., the smallest diameter 

 of its body 1 mm., and the greatest 1*3 mm. (near the basal end). 



The living animal is clear, colourless, almost transparent. The 

 tube in which it lives is circular and of a brown, horny-like sub- 

 stance, not easily ruptured, and is not confined to any special 

 substratum, but may occur embedded in limestone or between any 



