TIIF. INOIUiANlC CONS-nTrKXTS OK AIAKINK INVKRTKBRATES. 17 



ECHINODERMS. 



1. CRINOIDS. 



RECENT CRINOIDS. 



Tn 190G [I. W. Nichols '"' published a number of partial aualyses of marine invertebrates, 

 and in a crinoid, Metacrinus rotund lus froiu Japan, he found 11.72 per cent of magnesium 

 carbonate. This analysis attracted the attention of Austin H. Clark, and at his request two 

 other analyses of crinoids were made in the laboratory of the T'^nited States Geological Survey 

 by Chase Palmer, who also found that they contained abundant magnesia. These analyses, 

 which were published and discussed by Mr. Clark,-' will be considered in detail later. They at 

 once suggested that crinoids generally might bo highly magnesian and so play an important 

 part in the formation of. magnesian Umestones. 



In order to settle this question Mr. Clark supplied us with 24 specimens of recent crinoids, 

 representing 21 genera and covering a wide range of localities. These were analyzed by Mr. 

 Wheeler, and the analyses confii-med the origiiud supposition. All the specimens contamed 

 magnesium carbonate in notable proportions but varying in a most remarkable manner. The 

 data obtained are in detail as follows, beginning with the list of the specimens studied: 



I. Plilocnnus pinnalus A. H. Clark. Albatross stat^ion 3342, oft the Queen Charlotte Islands, British Columliia; 

 latitude, 52° 39' 30" N.; longitude, 132° 38' W.; depth of water, 2,858 meters; bottom temperature, 1.83° C. Mean of 

 two analyses. 



2. Floromelra (Hfperrima Clark Albatross station 3070, off the coast of Washington; latitude, 47° 20' 30" N.; 

 longitude, 125° 43' W.; depth, 1,145 meters; bottom temperature, 3.28° C. 



3. Psathyroimtrafragilis Clark. Albatross station 5032, Yezo Strait, Japan; latitude, 44° 05' N.; longitude, 145° 

 30' B.; depth, 540-959 meters; bottom temperature, 1.01° C. 



4. Peidametrocrinus japonicus P. H. Carpenter. Albatross station 5083, 34.5 miles off Omai Saki Light, Japan; 

 latitude, 34° 04' 20" N.; longitude, 137° 57' 30" E.; depth, 1,123 meters; bottom temperature, 3.39° C. 



5. Capillaster mulliradiata Linn6. Albatross station 5137, Philippine Islands near Jolo, 1 .3 miles from Jolo Light; 

 latitude, 6° 04' 25" N.; longitude, 120° 58' 30" E.; depth, 3t) meters; no temperature record. 



6. 'pachylonwtra patula Carpenter. Albatross station 503G, Philippine Islands, North Balabac Strait, 15.5 miles 

 from Balabac Light; latitude, 8° 06' 40" N.; longitude, 117° 18' 45" E.; depth, 104 meters; no temperature record. 



7. Catoptometra ophiura Clark. Same locality as No. 0. 



8. Hypalocrinus naresiaiius Carpenter. Albatross station 5424, Philippine Islands, 3.4 miles off Cagayan Island, 

 Jolo Sea; latitude, 9° 37' 05" N.; longitude, 121° 12' 37" E.; depth. 612 meters; bottom temperature, 10.22° C. 



9. Paramelra gramdata Clark. Albatross station 5536, Philippine Islands, between Negros and Siquijor, 11.8 

 miles from Apo Island; latitude, 9° 15' 45" N.; longitude, 123° 22' E.; depth, 502 meters; bottom temperature, 11.95° C. 



10. Craspedometra anceps Carpenter. Albatross station 5157, 3.3 miles from Tinakta Island, Tawi Tawi group, 

 Sulu Archipelago; latitude, 5° 12' 30" N.; longitude, 119° 55' 50" E.; depth, 32 meters; no temperature record. 



II. Ptilometra millleri Clark. Sydney Harbor, New South Wales, Australia; latitude, 33° 15' S.; longitude, 151° 

 12' E., approximately. 



12. Hathometra denlata Say. Fish Hawk station 1033, off Marthas Vineyard, Mass.; latitude, 39° 56' N.; longi- 

 tude, 69° 24' W.; depth, 329 meters; bottom temperature, about 7.8° C. 



13. Bythocririus robmtm Clark. Albatross station 2401, Gulf of Mexico, southeast of Pensacola ; latitude, 28° 38' 30" 

 N.; longitude, 85° 52' 30" W.; depth, 255 meters; no temperature record. 



14. Crinonutra concinna Clark. Albatross station 2324, north of Cuba; latitude, 23° 10' 35" N. ; longitude, 82° 20' 

 24" W.; depth, 59 meters; bottom temperature, 26.17° C. 



15. Isoainus decorus Wyville Thomson, stem. Off Habana, Cuba; latitude, 24° N.; longitude, 82° W.; approxi- 

 mately. 



16. Same as No. 15, arms. 



17. Endoxocrinus parrx Gervais, stem. Off Habana, Cuba. 



18. Same as No. 17, arms. 



19. Tropionutra picla Gay. Rio de Janeiro, Brazil; latitude, 25° 54' S.; longitude, 44° W., approximately. 



20. Promachocrinus kerguelensis Carpenter. Shores of the Antarctic Continent in the vicinity of Gaussberg; 

 latitude, 67° S.; longitude, 90° E., approximately; depth, 350-400 meters; bottom temperature, -1.85° C; salinity of 

 water, 3.3 per cent. 



21. Anthometra adriani Bell. Same locality as No. 20. Nos. 20 and 21 were collected by the German South Polar 

 Expedition. 



22. Zygometra microdiscus Bell. Am Islands, near the western point of New Guinea; latitude, 5°-6° S. 



23. Chlorometra-rugosa Clark. Near Rot ti, Lesser Sunda Islands; latitude, 10° 39' S.; longitude, 123° 40' E.; 

 depth, 520 meters. 



" Nichols, H. W., Field Columbian Mus. Pub. Ill, p. 31, 1906. " Clark, A. H., V. S. Nat. Mus. I'roc, vol, 39, p. 487, 1911. 



