638 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxxu. 



order to kill them in an expanded state. Glacial acetic acid serves very 

 well. Acid, however, mu.st be carefully avoided if it is intended to 

 use the specimens for systematic purposes, because the absence 

 of calcareous deposits in the skin usually renders exact determination 

 impossible. If there is a possibility of acid being- present in the 

 alcohol, add to the bottle a small portion of bicarbonate of soda or 

 some other harmless neutralizing agent. 



It is necessary to use a compound microscope in the examination of 

 holothurians, in order to determine the character of the calcareous 

 deposits in the skin. In the case of most synaptids and related forms 

 it is necessary merely to soak a piece of the bodj' wall for a few 

 moments in strong caustic potash solution and then mount it in gly- 

 cerin, which further clears the tissues. Permanent mounts are con- 

 veniently made in glycerin jelly. Many holothurians, however, have 

 so thick a bod}" wall that only the outer pigmented layer should be 

 taken. Often it is necessary to boil a piece of the skin in caustic 

 potash, especially when there is considerable pigment and one wishes 

 to free the deposits of encumbering tissue in order to draw or photo- 

 graph them. Deposits are frequently so closely crowded in the peri- 

 some that unless they are freed of tissue and spread out on a slide 

 it is impossible to gain an idea of their true character. 



The holothurians collected by the United States fisheries steamer 

 AJhatross among the Hawaiian Islands during the summer of 1902 

 proved to be less numerous in species than the collection of starfishes." 

 Nor were there so many individuals. The entire collection numbers 

 about 750 specimens and includes 37 species, of which 19 are new to 

 science, 5 are for the first time recorded from the Hawaiian group 

 and 2 are in too poor condition for naming beyond the genus. The 

 United States fisheries steamer Alhatross secured 11 forms already 

 reported from the islands, but failed to find 9 species known to occur 

 in the region. The Hawaiian fauna therefore includes 44 species of 

 holothurians, of which only 20 were known previous to the visit of 

 the fisheries steamer AThatross. To these may be added the two forms 

 which are too imperfect to be identified specifically, making a total 

 of 46 species. 



The shore and reef fauna is unmistakably tropical. Excluding those 

 littoral forms which appear to V)e confined to the Hawaiian Islands, 

 namely, Actinopyga obena^ Ilolothuria paradoaxi^ IL Iiajj/'olan/'w, H. 

 Tiumilis, H. hawaiiensis^ new species, H. amdifera, new species, H. 

 fuHco-olivacea^ new species, Oplieodesoma spectaJnlis^^ new species, and 

 Chiridota hawaiiensis^'^ new species, there remains a group of forms 



«See U. S. Fish Commission Bulletin for 1903, Pt. 2, pp. 897 to 1130, June 30, 1906. 

 ^ Closely related to Oplieodesoma glabra (Fiji Islands, Bohol, Guam, Saleyer, 

 Bima). 



<^ Near Chiridota rigida. 



