Holothurians.] SUBANTARCTIC ISLANDS OF NEW ZEALAND. 147 



arrangement in rows is obscure, and they become crowded round the opening of the 

 introvert. A few of the tube-feet are carried in with the invagination of the intro- 

 vert, where they are seen, on opening it up, in front of the pharynx and tentacles. 

 There are apparently 10 short much-branched tentacles, but, owing to the state 

 of contraction and the copious branching, it is difficult to make out their arrange- 

 ment satisfactorily. 



The pharynx is large, with 5 long retractor muscles attached posteriorly to the 

 radial longitudinal muscles well behind the middle of the body. There is apparently 

 no calcareous ring, but microscopic examination reveals the presence of 5 rudi- 

 mentary radials, ^-shaped, with the long arm pointing forwards. The total length 

 of each radial piece is only about 0-6 mm. The interradials are either absent or 

 are represented by a few granules. 



The pharjmx is followed by an elongated oesophagus, wnich terminates in a 

 slightly dilated muscular-looking " stomach " of about the same diameter as the 

 intestine which immediately follows it. On the outer wall of the oesophagus are 

 numerous large specks of dark-brown pigment, while a thin ring of similar pigment 

 marks the junction of the " stomach " with the intestine. The intestine is slightly 

 convoluted, and terminates in a short rectum attached to the body-wall by numerous 

 muscular threads. There is a pair of rather feebly developed, slightly branched 

 respiratory trees. 



There is a single well-developed convoluted stone-canal, situated dorsally, 

 and ending in an irregular nodular madreporite containing reticulate calcareous 

 deposits. There are two Polian vesicles, both long and slender, situated one on either 

 side of the mid-ventral line. Tube-foot ampullae are not recognisable, though the 

 tube-feet are well developed and have reticulate end-plates. 



The gonads consist of half a dozen rather short, stout, unbranched caeca, up to 

 about 5 ram. in length, springing from the end of a long genital duct at about the 

 middle of the body, and thus at a considerable distance behind the water-vascular 

 ring. Some, if not all, of the fully developed caeca contain rather large ova. There 

 are several minute undeveloped caeca at the point of attachment of the bunch to the 

 genital duct. 



The spicules of the body-wall consist of knobbed reticulate plates, about 0-12 mm. 

 long, with one end drawn out somewhat and dentate (figs, la, lb). They overlap 

 one another closely in the body-wall, and the dentate extremities point obliquely 

 outwards. There are apparently none of the more or less symmetrically ended, 

 reticulate, knobbed buttons, such as Ludwig figures for the species,* though some 

 of the spicules make a near approach to this form. A few smooth irregular reticu- 

 late plates also occur in boiled-out preparations of the integument (fig. Ic). 



The tube-feet possess well-developed circular smooth reticulate end-plates, 

 and the tentacles contain numerous smooth irregular reticulate plates or rods. 



Remarks. 



I have followed Ludwig, who gives an extensive synonymy, in regarding Semper's 

 two species — C. leonina and C. dvhiosa — as identical, although Semper's original 



 " Zoologiflche Jahrblicher," bd. ii, 1887, pi. i, fig. 1. 



