■n\' H. L. kesteven. 675 



shown ill tlie same iigure. The fourth and fifth pairs ( Fii^'. 8) are 

 exactly alike; they are biramous, the protopodite of one segment 

 is broad and short. The endoiaodite, also unisegmented, is ilattened, 

 and has all the appearance of being chelate, but no joint is present. 

 The expodite is chelate, of two segments; superficially it bears a 

 close resemblance to the endopodite. These a^jpendages are 

 doubtless legs. 



With the exception of a sliglit constriction, not always present, 

 between the third and fourth pairs of appendages, there are no 

 indications of segmentation whatsoever. 



The appendages present striking peculiarities, which has called 

 for special care in their description. Difficulty has been caused, 

 too, by their flexibility, so that though, between tliirty and forty 

 specimens have been examined, only in three are the second pair 

 clearly discernible; whilst, in four of the specimens only, does one 

 see the third pair clearly. The first, fourth, and fifth pairs are 

 clearly visible in some eight or nine specimens. 



In the absence of any evidence to aid me, I have adojjted Mayer's 

 names for the appendages (Z.c). 



Body-Wall. — Beneath the cuticle is a syncytial ( T) flattened epi- 

 thelium, difficult to make out on account of its delicacy. Deep to 

 the epithelium are the longitudinal muscle-bands; each of these is 

 composed of three or four plain muscle-fibres, as seen in trans- 

 verse section. There is apparently no anastomosis of tliese muscle- 

 strands. 



Perforating the body-wall are the ducts of numerous excretory 

 ( ? ) glands. Each gland is composed of several large, flask or 

 spindle-shaped cells, whose cytoplasm is very granular, and whose 

 nucleus is relatively small, and poor in cliromatic material, with 

 one well defined nucleolus. The "duct" is formed by the fusion of 

 the necks of the component cells, and in its wall are several intense- 

 ly staining granules resembling cocci in size and shape (Fig. 17). 

 There is no true duct formed, the condition being rather, a group 

 of unicellular glands perforating the body-wall by a common aper- 

 ture. Similar glands are described in Ive balanoglossi by Mayer. 

 Tliese glands are most abundant anteriorly. 



