Hololhurians.] SUBANTARCTIC ISLANDS OF NEW ZEALAND. 161 



connected by transitional forms with much larger, knobbed, reticulate plates 

 (figs. 2h, 2k). There are also irregular smooth reticulate plates of larger size (fig. 21), 

 and smooth circular end-plates. All these forms occur in a boiled-out preparation 

 of the integument. 



Remarks. 



There can be no doubt of the close relationship of this form with C. brevidentis, 

 with which it is now generally admitted that my Colochirus calcarea is specifically 

 identical. Unfortunately, nothing is known of the internal anatomy of the type 

 of C. hrevidentis ; that of C. calcarea, however, was described in my first paper on 

 the New Zealand Holothurians,* and exhibits certain differences as compared with 

 the Camley Harbour form. Thus, in C. calcarea there appears to be no muscular 

 stomach, and the respiratory trees are short and merely digitate instead of copiously 

 branched, and the genital caeca also appear to be short.. The difference in the 

 calcareous ring has already been referred to. It is doubtful, however, if any of 

 these differences are of more than varietal value. 



The occurrence of C. hrevidentis at Juan Fernandez, as recorded by Ludwig,f 

 forms another interesting case of agreement between the marine fauna of New Zea- 

 land and that of South America. 



Chirodota benhami, sp. nov. 



This species is represented in the collection by two specimens from Masked 

 Island, in Camley Harbour, where it occurs under stones. 



The larger of the two is about 21 mm. in length by 2-5 mm. in diameter. 



The colour is now (in alcohol) yellowish-grey with a sHght pinkish tinge, and 

 the surface is transversely corrugated and papillated. There are 10 short tentacles, 

 each with 4 or 5 pairs of digits, the terminal pair being conspicuously larger than any 

 of the others. 



The alimentary canal exhibits 3 limbs, forming the usual S-shaped figure, and is 

 a good deal sacculated in its present condition. The calcareous ring is slender, and 

 consists of 10 simple slightly curved rods, joined end to end. The water-vascular 

 ring is of a pale-purplish colour, and gives off a single large ventral Polian vesicle 

 of the same colour, consisting of a slender stalk with an oval dilated sac at its 

 extremity. The madreporic canal appears to be represented by a minute dorsally 

 placed body. 



The gonads consist of a pair of bunches of short, slightly branched ovarian caeca, 

 each with only about 2 or 3 branches, situated close to the anterior extremity of the 

 body-cavity, right and left of the dorsal mesentery. 



Numerous large " ciliated funnels " are scattered singly in the neighbourhood 

 of the dorsal mesentery. (Similar funnels occur in C. dunedinensis, though not 

 hitherto noted.) 



Both longitudinal and circular muscles are well developed in the body-wall. 



[The smaller specimen appears to be immature ; no gonads are recognisable. 

 The alimentary canal is apparently not looped in an S-shape, but much sacculated, 

 and perhaps slightly convoluted.] 



* .loum. Linn. Soo., Zool., vol. xxvi, p. 22. 



t " Die Holothurien der Sammlung Plate," Zoolog. Jahrbiich., suppl. iv, heft 2, 1898. 



