108 PROF. A. DENDY AND ME. E. HINDLE : ADDITIONS TO 



being no differentiated oesophagus. It exhibits the usual S-shaped curvature. 

 The first limb, extending to the posterior end o£ the body-cavity, is slightly 

 convoluted ; the middle part is almost straight ; and the last limb is quite 

 straight, and is supported by the right ventral mesentery. There is no well- 

 marked dilatation o£ the terminal part o£ the intestine to form the cloaca, and 

 there are no radially arranged muscle-fibres in that region ; a fact which may 

 doubtless be correlated with the feeble development of the respiratory trees. 



The latter extend almost to the anterior extremity of the body, but are 

 very little branched and differ markedly from the respiratory trees of 

 P. dearmatus. They unite immediately before opening through the dorsal 

 wall into the posterior end of the intestine. 



The water-vascular ring (fig. 14, a.c.) surrounds the pharynx immediately 

 before the latter narrows into the intestine. The Polian vesicle (p.) is a long 

 thin tube ending in a pear-shaped dilatation, and arises from the ventral side 

 of the ambulacral ring. It is 1'7 cms. in length ; the diameter of the narrow 

 portion is 0*5 mm. and of the dilatation 3'5 mm. The madreporic canal (?n.) is a 

 very slender sinuous tube arising from the dorsal part of the ambulacral ring, 

 and running posteriorly to end in a somewhat large madreporite, attached to 

 the dorsal mesentery. 



The gonads (^.) consist of two bunches of very long filaments situated right 

 and left of the dorsal mesentery a little behind the middle of the (retracted) 

 body. The left bunch is larger than the right and its branches extend to both 

 ends of the animal and are very numerous *. The genital duct {g.d.') runs 

 forward in the dorsal mesentery from the junction of the two bunches of cseca 

 to open to the exterior on the dorsal surface. 



The spiculation and the structure of the calcareous ring distinguish this 

 species from all other members of its genus. 



The tables differ markedly from those of P. intercedens, Lampert, and this 

 is the only other known species of P seudocucnmis with only two rods to the 

 spire of the table. P. bicolumnatus is also distinguished from this species 

 by the number of the tentacles and the presence of only one Polian vesicle. 



Caudina coeiacea, Hutton, sp. 



1872. Molpadia coriacea, Huttou, Cat. Echinoderm. N.Z. p. 17. 



1879. Caudina ? {Echinosoma ?) coriacea, IIuttoD, Trans. N.Z. Inst. vol. xi. p. 337. 



1883. Caudina meridionalis, Bell, Proc. Zool. Soc. Lond. pp. 58-59, pi. 15. fig. 1. 



1885. Molpadia coriacea, Lampert, Die Seewalzen, pp. 208-209. 



1886. Caudina meridionalis, Lampert, Die Seewalzen, pp. 210-211. 



188G. Caudina coriacea, Theel, Chall. Reports, vol. xiv. pp. 47, 54-55, pi. 3. fig. 4. 

 1897. Caudina coriacea, Dendy, Proc. Linn. Soc, Zool. vol. xxvi. pp. 28-32, pi. [3. 

 ficrs. 9-18. 



Only a few of these branches are shown in fig. 14. 



