ASEX1 \I REPRODUCTION IX THK STAKIIMi, 



SCLERASTERIAS. 



\V. K. FISHER.' 



In sea si !f-division involving the disk occur- nun h m<>rr 



ly than aut<>tomy of rays only. The fir>t o-nditinn. ternu-d 

 li--i|>arii\ . i- .1 form of asexual propagation and in tin \--.Tiid.r i> 

 i -hara< tcri-ii( of three genera, namely, Coyfinastcn't:^ both the 

 Kilntniiriii type and the tennispina tyj and 



Stephanasterias. In the last genus asexual ivprodmtion app< 

 tn IK- fully as important as gametic. In Linckin, la-lmi^i' 

 ditlciciii onk-r, an entire animal may be re^rm-rainl from a cast- 

 oil ray. Tin- curious comet forms originate in thi> main < 



In ( ex inasterias and Stephanasterias fissi|).u ii\ pi-i>i-t- in adult 

 lift . Inn in Sclerasterias 3 it is strictly confined to a \n\ immatuiv 

 >ia;^i-. iii \\hich the number of rays is predominantly wv, \\lu ; 

 in ilu- adnli it i> li\r. Furthermore these \unx dii;i i so 



Marine Station of Stanford t_"ni\vr-ity. 



I "i iiKiiit-s set Fisher, "Asteroidea of the North I' Hull. ;'. I 



M n- . i<ji i . pint i- .j.s, Fif{8. i and 2. 



ila \ figured in Fisher. "The >t.u ii-lii - "i tin- II 

 l-l.iii.!-. i -- Fiah. Conun. Bull, for 1903. port 3, plal 

 is in tin- uiti : stage. The closely related S. hypacotttha i- tixu: 



i tin- Philippine Seas." Bull. 100, U. S. Nat. M pi. 141. 



Mi es of Sclerasterias resemble Marthasteria tin- \vrll-kni>\\-n 



ir. The genus is a fairly homogene<iu~ KT^UP "i tliirti i -n ktinwn 



:--l.iti-i| ! .isterias. Its type. S. guernei, \\-.\ a highly 



.ii.ir ~in.il! -IM -i u-s but proves on examination to \>t- immatui. M. n, 



\vitli i, a name of later ap :i aim. UK tin- tin: 



U- iiii-iuinned: i'. altxandri (Lud\\ : >.<>ntri>i 



l-'l.ni.l.i i.. it.irhados; 5. euplecla (1 Hawaiian I>Uni': 



-tan .la i unha; 5. fKemi Perrier, genotype, Bay of l iollis 



(Him. .n . N. \\ /. alatul; 5. lanneri (\'errill), Atlantic ; l nit. .1 > 



>'. /. : !ii-r. in \v species, Monterey Bay, Calit.'inia. 



!' ni( i States that hi- K.-IIUS Ly taster is fissiparous. I ian cunlirm tin- tr..in an 

 xaiiiinati.in .'t tin- t\|>. -, at Paris. But the types are only very immat . 



lllrlls nt Costil 



I ..l the lainily Asteriida?, SIT Ki-lu-r, Anna: \'nl. 



\ ! I'P- 247. 595. 



171 



