THE IIOLOTIIURIDEA. 

 B 



471 



Fm. 136. Synapfa flirntata nnd inhcerens (After Bnnr.) l 



A, larva with the bilateril ciliated hand, and wheel-shaped calcareous plates; 

 ventral view. a. month and millet: />. stomach: c, intestine and anus; </, pars 

 of the enterom'le (sausage-shaped bodies) at the sides of the. stomach; f, rndi- 

 ment of the ambulacra! vascular system. B, further advanced condition ol the 

 larva in which the oral aperture is obsolete (the so-called " pnpa-stas:e"). and the 

 cilia are arranged In zones, i, tentacula; A". Polinn vesicle ; /. tin- U.n-ittidinal 

 muscles of the body-wall. C. a voun<r Si/nnpta. in which the ciliated zones have 

 disappeared; with' Its five tentacles and the wheel-sliaped calcareous 1x>die8 at 

 its hinder end //;. the madrenoric canal which now opens into the cavity of the 

 body. I), a voting Synapfn hihannx with anchor-shaped calcareous picaUt, ex- 

 cept at the hinder end of the. body, when- they are small and polygonal. E, lon- 



"BeitrSge zur Naturgeschichte der Synapta digttaia." ("Nova Acta," 

 xxxi., 1864.) 



