(115) 



to the blind ena of tl:e nephriciial caiialy. 



The "neuropore" and "subneural t^ldsad" which Mastenrian has 

 aescribea cio uot exist in the Actinot rocnae that I have exaMned 

 althout^i imperfeetl;/- pregerved specimens show unusual struc lures 

 which miglrit be taken for these organs, 



Masterman's "subneural sinus" is not present either al- 

 though there is a space below the gant-,lion whicl: is free from 

 mesodennal strands. The "atrial grooves" which Mastenaan says 

 exist are present in tiie larvae 1 have studied but 1 cai-inot con- 

 sider tl^at they have ti:e significance ti.at he assigns- to them. 



are 

 Occasionally grooves ^ f'ound which migi.t be comparable to Master- 

 man's "oral grooves" but they are duo to imperfect fixation. The 

 stomach diverticula exist in one species that 1 nave examined 

 but they do net impress me as being of notochordal nature as Roule 

 and Mastennan have claimed. 



There is a subepidermal layer of nervous tissue throughout 

 the body. Extending, anteriorly from the ganglion, which is sit- 

 uated on the median dorsal surface of the hood, are three longi- 

 tidunal nerves which Anally become continuous with a nervous 

 ring running around the edge of the hood. l^rom the posterior 

 side of the ganglion two parallel tracts of nerve fibers issue 

 and pas. posteriorly alon, the dorsal collar wall until they 

 reach the circle o+' tentacles -^.ere most of tnem follow the line 



