374 BULLETIN 82, UNITED STATES NATIONAL MUSEUM. 



HATHROMETRA 8ARSII. 



Professor Sars gives the period of sexual maturity in the Lofoten Islands as 

 June. He found the youngest prebrachial stage at the beginning of July. 



PENTAMETROCRINU8 TUBERCULATUS. 



The ovaries of a specimen dredged off southern Japan on October 13, 1896, 

 in 169 fathoms, contained well-developed eggs. 



PEXTAMETROCRINUS JAPONICUS. 



Well-developed eggs \vere found in the ovaries of a specimen dredged off 

 southern Japan on August 23, 1906. 



PENTAMETROCRINTI8 VARIANS. 



Eggs apparently of full size were found in the ovaries of specimens dredged 

 off southern Japan between August 13 and October 20, 1906. 



The species which have been found spawning in the different months are 

 as follows: 



January: Comactinia meridional^, Gatoptometra ophiura, Antedon mediter- 

 ranea, Coccometra nigrolineata, Leptoinetra phalangium. 



February : Comatella nigra, Amphimetra spectabUis, Amphimetra parilis, 

 * Antedon mediterranean, Coccometra hagenii. 



March: Comissa spanoschistum, Tropiometra picta, Antedon mediterranea. 



April: Comissia spanoschistum, Tropiometra picta, * Antedon mediterranea. 



May : Cenometra delicata, Antedon bifida, Antedon mediterranea. Antedon 

 adriatica. 



June : Antedon bifida, Antedon mediterranea, Antedon adriatica, Hathrometra 

 sarsii. 



July: Comissia Jittoralis, Antedon bifida, Antedon mediterranea. 



August : Calyptometra lateralis, Antedon mediterranea, Compsometra loveni, 

 Pentametrocrinus japonicus, Pentametrocrinus varians. 



September : Comanthus japonica, Tropiometra macrodiscus, Antedon mediter- 

 ranea, Compsometra loveni, Psathyrometra fragilis, Pentametrocrinus varians. 



October: Comanthus japonica, Antedon mediterranea, Pentametrocrinus tuber- 

 culatus, Pentametrocrinus varians. 



November: * Antedon mediterranea. 



December : * Antedon mediterranea. 



In the case of Antedon mediterranea the asterisk (*) indicates the months in 

 which the greatest number of egg-bearing females are found. 



In regard to two species, Antedon bifda and Hathrometra sarsii, there seems 

 to be a definite breeding season in the late spring and early summer, from May to 

 July. Both these species live in the northeastern Atlantic, on coasts where the 

 water undergoes considerable seasonal change in temperature and in plankton 

 content, and the definiteness of the spawning period is probably connected with 

 this seasonal change. 



