247 



III. Geographical Distribution. 



In my work "Die Echinodermen-Larven d. Plankton-Exped." p. 108 — 

 114 the distribution of the Echinoderm larvae and some of the problems 

 connected therewith were discussed at some length. Since then only very 

 little additional information on this subject has been obtained. MacBride 

 in 1903 published a "Report on a small collection of Echinoderm larvae 

 made by Mr. George Murray during the Cruise of the "Oceana" in Novem- 

 ber 1898" '^); only one species, the larva of Luidia Sarsi, is recorded there, 

 from the Atlantic off S. W. Ireland (52° 4' N., 12°27' W.). Gemmill^) has 

 recorded some larvae of Luidia ciliaris Ukewise from off S. W. Ireland 

 (30 — 60 miles off Tearaght Island), and one single specimen of "Brachio- 

 laria hibernica" from 50 Miles N. by W. of Eagle Island, W. of Ireland. In 

 my report on "Die Echinodermen-Larven d. deutschen Siidpolar-Expedi- 

 tion" (p. 109) a Spatangoid-larva is recorded from 10°17' E. 28°45' S., that 

 is about in the mid-Atlantic between Cape and Patagonia, at a depth of 

 nearly 5000 Meters. Apart from this highly interesting find only larvae 

 taken near the littoral regions are recorded in that work, as also in Mac- 

 Bride's reports on Echinoderm larvae from the Antarctic Expeditions 

 (National Antarctic Exped. ; British Antarctic ("Terra Nova") Exped.). The 

 existence of quite a considerable number of pelagic Echinoderm larvae in 

 the Antarctic Seas has been estabhshed herewith; but this fact, though of 

 very considerable interest, does not concern us here. Referring still to the 

 " Stellosphasra mirabilis" recorded by Koehler & Vaney from the vicinity 

 of the Azores (ca. 36 — 40° N. 19 — 30° W.) mention has been made of, so 

 far as I know, all records giving observations on the occurrence of Echino- 

 derm larvae in the open Ocean.*) 



As stated in the Introduction (p. 10) I have at various occasions made 

 efforts to bring together some more facts relating to the problem of the 

 distribution of Echinoderm larvae over the open Ocean. Observations made 

 during the passage over the Indian Ocean from Aden to Singapore gave 

 the result that, while Echinoderm larvaj were found in good numbers in 

 the Gulf of Aden, none were observed until near the Maldives, but from 

 there larvae occurred the whole way across the Bay of Bengal. This would 

 appear to indicate that larvae do not occur in the great Arabian Sea. I 

 would, however, not regard the negative result as conclusive, because the 

 samples were taken there at day time. Later on samples were taken also 

 by night, and these were invariably richer than those taken by day, in 



1) Ann. & Mag. Nat. Hist. VII. Ser. XI. p. 477—78. 



2) J. F. Gem mi 11. On a new brachiate Asteroid larva and on the advanced Bipinnaria 

 of Luidia ciliaris (Philippi) Gray. Proc. R. Phys. Soc. Edinb. XIX. 1915. 



3) See, however, the paper by Stanley Gardiner mentioned below (p. 251). 



