Igg BULLETIN S2, UNITED STATES NATIONAL MUSEUM VOLUME 1 



Formosa Channel; 64 meters; Captain Suensson, November 23, 1901 [A. H. Clark, 

 1909] (1. U.S.N.M., 35036). 



Dr. Mortensen's station 1; Biolo^cal station, Misaki, Japan; shore; April 23, 

 1914 [Gisl6n, 1927] (4, CM.). 



Dr. Mortensen's station 3; Misaki; shore; April 29, 1914 [Gislen, 1927] (1, CM.). 



Dr. Mortensen's station 10; off Kiu-Shiu, Japan (lat. 33°41' N., long. 12S°50' 

 E.); 137 meters; sand; May 17, 1914 [Gisli^n, 1927] (1,CM.). 



Dr. Mortensen's station 22; Misaki, Japan; 0-4 meters; rocky; June 16, 1914 

 [GisKm, 1927] (3, CM.). 



Dr. Mortensen's station 23; Misald; 2-4 meters; on roots of Laminariacea; June 

 19, 1914 [Gisldn, 1927] (5, CM.). 



Dr. Mortensen's station 25; Okinose, Sagami Sea, Japan; 183 meters; hard 

 bottom; June 26, 1914 [Gislen, 1927] (2, CM.). 



Cape Sima, Japan; Dr. G. Jeffreys [A. H. Clark, 1929] (1, B.M.). 



Tsingtao, China: entrance to Kiaochow Bay and aroimd Takungtao and Si- 

 aokungtao; 15-65 meters; rock, stones and broken shells [Chang, 1948]. 



Off Amoy, Fukicn Province, China (lat. 24°06' N., long. 11S°25' E.); 36 meters; 

 bottom temperature 24.5° C; H. Christensen; August 10, 1912 (CM.). 



San-Tu, Fukien Province, China; Dr. Cheng C3, B.M.). 



Geographical range. — From Fukien Pro\'ince, China, and the Formosa Channel 

 to Tsingtao on the Yellow Sea eastward to Tokyo Bay in Japan. 



Bathymetrical range. — From the low tide mark and just above it do\vn to 180 meters. 



Occurrence. — Dr. Th. Mortensen found this species to be fairly common on the 

 rocky shores near the biological station at Misaki from about low tide mark to some- 

 what deeper water. It was often found on the under side of rocks which one could 

 turn over and also among the roots of laminarians and other algae. 



Early stages. — On his return to Copenhagen Dr. Mortensen found that a few of the 

 specimens of this species which he had collected at Misald carried a considerable num- 

 ber of embrj'os on the pinnules. These proved to represent only two stages, showing 

 that in this species, as in the other species of Antedon, the eggs are extruded contempo- 

 raneously, apparently as a result of the stimulating effect of the sperm from some male. 



Judging from the ripe eggs within the pinnules of the preserved specimens the eggs 

 are rather small, onty about 0.25 mm. in diameter. They remain attached in clusters 

 to the pinnules about the opening through which they were extruded. The egg mem- 

 brane docs not appear to have any structural peculiarities, but is simple, as in other 

 species of Antedon, serving only as a means of attachment and not as a floating apparatus 

 as in Tropiometra. It appears to be very spacious, affording ample room, so that the 

 embryo is not globular, as is usual in Antedon, but while still lying within the membrane 

 has its natural elongate shape. 



Dr. Mortensen says that from the material at hand it is evident that the embrj'os 

 remain wathin the egg membrane until fully formed and ready to attach themselves 

 and transform into pentacrinoids. It may thus be concluded with a fau- degree of 

 certainty that they have only a very short free swimming period, and this supposition 

 is strengthened by the fact that the pentacrinoids were found very close to the localities 

 where the adults were secured. 



The cleavage, the formation of the archenteron, and the formation of the entero- 

 coele and hydrocoele sacs was not observed. 



