26, of a slender plagiotriaene with relatively long clades of a large dark specimen from South Molokai 

 (race II). 



27. — A large whitish specimen from South Molokai (race I, form C); natural size; phot. Zeiss, anastig. 



480/412 mm. 



28. — A large dark specimen from South Molokai (race II); natural size; phot. Zeiss, anastig. 480/421 



mm. 



29-35. — Rhabd megascleres; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6: 



29-31, more or less amphiox-rhabds tapering towards both ends, of a large whitish specimen from 

 South Molokai (race I, form C) ; 



32, stout and short, somewhat irregularly cylindrical amphistrongyle, of a large whitish specimen 

 from South Molokai (race I, form C) ; 



33, 34, sharp-pointed amphioxes, of a small dark specimen from South Molokai (race I, form B) ; 



35, pointed ampliiox of a large dark specimen from South Molokai (race II). 



36-41. — Groups of microscleres from centrifuge-spicule preparations; magnified 300; phot. Zeiss, 

 apochr. 4, compens. oc. 6: 



a, isoactine centrotyle microrhabds; b, anisoactine microrhabds;' c, acanthtylasters; d, young 

 aspidaster ; 



36, 39, 41, of a large whitish specimen from South Molokai (race I, form C) ; 



37, of a small dark specimen from South Molokai (race I, form B); 



38, of a large dark specimen from South Molokai (race II) ; 



40, of a middle-sized fight-coloured specimen from northeast Hawaii (race I, form D). 

 42-48. — Rhabd megascleres; magnified 100; phot. Zeiss, apochr. 16, compens. oc. 6: 



42, 43, large, more or less pointed amphioxes, of a middle-sized light-coloured specimen from north- 

 east Hawaii (race I, form D) ; 



44, style, abruptly bent close to the blunt end, of a middle-sized light-coloured specimen from 

 northeast Hawaii (race I, form D) ; 



45, amphistrongyle, of a middle-sized light- coloured specimen from northeast Hawaii (race I, 

 form D); 



46, small blunt amphiox, of a middle-sized light-coloured specimen from northeast Hawaii (race I, 

 form D) ; 



47, 48, small, sharp-pointed amphiox. of a small, partly light, partly dark, specimen from South 



Molokai (race I, form A). 



