HOLOTHUEIAJSrs OF NEW ZEALAND. 49 



The original description runs as follows : — " Elongated, rather 

 slender. Skin, smooth. Feet, scattered sporadically over the 

 ventral surface, apparently none on the back. Tentacles, 20. 

 Anus, round. Back, pale purplish brown. Yentral surface, 

 dirty white, with scattered brown spots. Length, 4| inches. 



" Cape Campbell. Presented to the Museum by Mr. C. H. 

 Robson, to whom I have much pleasure in dedicating it." 



I am informed by Professor Parker that the type specimen 

 was sent to the Colonial and Indian Exhibition and thence to 

 the British Museum. Nothing further is known of the species. 



HOLOTHUEIA LACTEA, Theel. 



Holothuria lactea, Thed, * Challenger' Holothurioidea, p. 183, pi. x. 

 figs. 9, 15. 



This is a deep-water species, obtained by the ' Challenger ' at 

 Station 169, East of New Zealand, at a depth of 700 fathoms, 

 and also at Station 78, in the North Atlantic, at a depth of 1000 

 fathoms. 



Appendix. 



On the Structure and Growth Changes of the Wheels 

 in Chirodota dunedinensis. 



The fully-developed wheel lies in the integument with its two 

 faces parallel to the surface of the body. The two faces differ 

 very markedly in structure, and, as the position appears to be 

 constant, we may conveniently distinguish them as the inner and 

 outer faces respectively. 



The outer face is shown in PL 3. fig. 1 ; from which it will be 

 seen that there is a small round hole in the centre, from which 

 the six flattened spokes radiate to the margin of the wheel. At 

 the margin the ends of the spokes are connected together by the 

 rim, which is strongly incurved on this face and provided with a 

 finely serrated edge. 



The inner face of the wheel is shown in fig. 2. Here we see in 

 the middle a six-rayed cross, covering over a central depression 

 or cavity in which lies the small round hole already seen on the 

 outer face. The rays of the cross are much narrower than the 

 corresponding spokes, into which they merge at their outer ends, 



Eig. 2 a represents an optical vertical section of the wheel ; 

 passing through two spokes, through the centre of the cross and 

 through the hole in the outer face, which is here placed lower- 



XINN. JOUBN. — ZOOLOGT, VOL. XXVI. 4 



