186 



Proceedings of the Royal Physical Society. 



Fig. 7. 



Diagram of the peribsemal sinuses and of the hremal tissue in the madreporic region of a 

 large adult Solaster. The view is from above and slightly from the outside, the centre 

 of the starfish disc being towards the lower part of the page. 



ab. s. (d) and ab. s. (s) dextral ' and sinistral 1 limbs respectively of aboral perihsemal 

 sinus. 



ax. org. the axial organ lying vertically within the axial sinus, but for purposes of 

 illustration here shown as if seen more from the outer side than are the rest 

 of the structures. At it is passing downwards towards the oral haemal 

 ring. At the aboral end it, is continued into the tissue invaginating the 

 dorsal sac. 



ax. s. . axial sinus, wider than natural in the diagram, and like the axial organ con- 

 tinued at on the oral direction. The stone canal with its characteristic 

 internal fold is indicated to the sinistral side of the axial organ, but no 

 attempt has been made to illustrate the relations of the aboral ends of stone 

 canal and axial sinus. (For this see Figs. 1 to 5.) 

 dorsal sac. 



d. s. 



(I. s. 

 h. abs 



(d) and g. s. (s) dextral and sinistral genital sinuses. 



haemal tissue within the dextral and sinistral limbs respectively of the 

 aboral peril) aanal sinus. 

 h. spg. . dextral and sinistral epigastric haemal tufts. 

 h. g. x. . haemal tissue of genital sinuses. 

 no. . ovary. si. c. . stone can;il. 



1 Sec note at loot of page 1 74. 



