24 PEOr. A. DEKDT OK THE 



the hitherto almost entirely unknown internal anatomy and 

 spiculation, and the results are giA'^en in the body of this paper, 

 illustrated by figures of the characteristic spicules and other parts. 



Four new species are described and illustrated, viz., Oucumaria 

 Suttoni, Colochirus ocnoides, .ColocJiirus calcarea, and Psolus 

 macquariensis. 



The ' Challenger ' specimens of CTiirodota australiana are sbown 

 to be probably identical with C. dunedinensis^ the sigmoid spicules 

 of the latter having been hitherto unrecorded ; so that it is very 

 doubtful if the Australian species has been found in New Zealand 

 waters at all, unless indeed the two be identical. 



Echinocucumis alba, Hutton, is shown to be a Colochirus. 



Throne Irevidentis, Hutton, is shown to be almost certainly a 

 Colochirus also. 



Thy one caudata, Hutton, and Thyonidium rugosum, Theel, are 

 shown to be identical with Thyone {Pentadactyla) longidentis, 

 Hutton. 



Sticliopus sordidus, Theel, is shown to be identical with Holo- 

 thuria mollis, Hutton, which is really a Stichopus. 



Allowing for these determinations in synonymy, the number 

 of known species of New Zealand Holothurians now becomes 

 seventeen, but four of these, viz., Synapta incequalis, Gucumaria (?) 

 Thomsoni, Cucumaria{?) turbinata, and Solothuria Sobsoni, are 

 still very imperfectly known and may prove to be synonymous ; 

 while two of them, Y\z.,Ankyroderma Marenzelleri and Holoihuria 

 lactea, were obtained by the ' Challenger ' in deep water, and 

 perhaps ought scarcely to be included in the New Zealand fauna. 



It is remarkable that no fewer than three of our New Zealand 

 species, viz., Gucumaria Huttoni, Colochirus alba, and Colochirus 

 ocnoides^ are provided with overlapping dermal plates, a condition 

 which elsewhere does not appear to be at all common in the 

 group. 



Theel has already pointed out that the genus Colochirus is 

 especially characteristic of the Indian and Pacific Oceans, so that 

 it is not surprising to find that no fewer than four of our species 

 are referable thereto. 



I have not thought it necessary to give figures of the general 

 anatomy because no strikingly new anatomical facts have 

 been discovered, and descriptions of the internal organs appear 

 generally to be sufficient for systematic purposes. 



Perhaps the most interesting anaton^ical result is that Ghirodota 



