148 



depths through which it has thus far been observed to range : 

 Synajyta tenuis Ayres — littoral to six fathoms; Chirodota are- 

 nata Gould — shoal water ; Sclera dactyla briareus Le Sueur — 

 littoral to four fathoms ; Thyonidium elongatum Ayres — thirty 

 fathoms to forty ; T. musculosu?n Ayres — twenty fathoms ; 7\ 

 glahrum Ayres — thirty fathoms to forty ; Stereoderma unisemita 

 Stimpson — eighteen fathoms to forty ; Botryodactyla graridis 

 Ayres — seventeen fathoms to fifty; B. affinis Ayres — one 

 fathom to fifty ; Cuvieria Fahricii Duben and Koren — six 

 fathoms to twenty; Psoitis Iccvigaliis Ayres — sixteen fathoms 

 to twenty-five ; P. granulaius Ayres — thirty fathoms ; P. phan- 

 tapus Lin. — sixteen fathoms to twenty. 



A glance at this catalogue is sufficient to show that with a 

 single exception, no European species is included in it. One 

 type of the genus Psoitis resembles so much the Linnean Phan- 

 lapus, that until the point can be settled by direct comparison of 

 specimens, it is not deemed advisable to impose a new specific 

 name. Still, even here we shall probably find that they are only 

 allied forms. Of the other species, but one can be said to exhibit 

 much resemblance to European types. In this respect a marked 

 contrast exists between the Holothuridse and other divisions of 

 the Radiata. 



It will be noticed, also, that most of the species here desig- 

 nated inhabit deep water, and that of some the range is quite 

 extensive. The depths, however, as given above, cannot at all 

 be considered absolute ; the numbers only represent the limits of 

 our knowledge at the present time. Every additional opportu- 

 nity for observation brings to light habits and localities previously 

 unknown, and we have entire reason to believe that species 

 hitherto obtained only in deep water will yet be found in other 

 circumstances within the range of the tide. The species which 

 still remain undescribed will also illustrate the same point. 



Dr. Storer, in behalf of the Committee appointed to 

 nominate Acting Curators, reported the name of W. O. 

 Ayres as Acting Curator of the Crustacea and Radiata, 

 and Dr. Silas Durkee as Acting Curator of Ichthyology in 

 the place of Mr. Ayres. The report was accepted, and the 

 gentlemen nominated were elected accordingly. 



