HOLOTHUEIANS OF NEW ZEALAND. 27 



in the skin ; tentacles shield-shaped, produced at the edges into 

 finger-like processes (Tentacula peltato-digitata)." 



Professor Parker has very kindly sent me six specimens of 

 this beautiful little Holothurian, three preserved after treatment 

 with osmic acid and three after treatment with picric. Although 

 it is ten or twelve years since they were bottled, the specimens 

 are in an excellent state of preservation, especially those treated 

 with picric acid. I am thus able to add the following particulars 

 to the above description. 



The spicules (which have not been perceptibly injured by the 

 aiethod of preservation) are of two kinds : — (1) Wheels (figs. 1- 

 6), about 0'16 mm. in diameter, and each with six spokes {vide 

 Appendix). (2) Contorted sigmoid spicules (fig. 7), resembling 

 the siliceous spicules known as "contort sigmata " in sponges; 

 measuring about 0"11 mm. from bend to bend. Both kinds of 

 spicule are abundant and both are loosely and irregularly 

 scattered through the interambulacral integument, not aggre- 

 gated in papillae ; but whereas the sigmata occur abundantly in 

 all the interambulacra, the wheels appear to be entirely absent 

 from the two interambulacra of the ventral surface. 



There is a pharyngeal skeleton in the form of a slender 

 calcareous ring of ten simple pieces, of which the ends touch 

 (fig.8)._ 



The integument is thin and translucent, but the five longi- 

 tudinal bands of muscle are well developed. There are, of 

 course, no retractor muscles. 



The alimentary canal is not thrown into loops but runs straight 

 from mouth to anus, and is slightly convolute by the con- 

 traction of the body. 



There is a single elongated, slender Polian vesicle, placed 

 ventrally ; and what appears to be the madreporic canal is very 

 small and situate dorsally. 



The sexes are distinct, and the females may be readily dis- 

 tinguished by the relatively large eggs in the ovary, which give 

 that organ a coarsely granular appearance very different from that 

 of the smooth-looking testis. The reproductive organs have the 

 same form and relations in both sexes, consisting of a few long 

 slender tubes hanging down from the end of the short genital 

 duct, which lies dorsally at the anterior end of the body. The 

 longer tubes extend back nearly to the hinder end of the body. 



The condition of the reproductive organs is especially inter- 



