Plaie XXIV. 



CrIBRELLA SANGUINOLENTA, LxjTK. 



•44. M;uli-e[>oiic portion of a radial section of a specimen wliose Pi:=24 mm. x 00. 

 45. Ditto, 84 sections (eacli=:10 (i ) on the right side of tlie foregoing, x 60. 



SOLASTER ENDECA (L.) 



40. Madreporic portion of a radial section of a specimen whose Pi^G.5 mm. x CO. 



AsTERiNA GiBBOSA (Penn.). 



47. Madreporic portion of a radial section of a specimen whose E^IO mm. x 00. 



ASTROPECTEN SP. 



48. Madreporic portion of a radial section of a specimen whose E=50 mm. x 54. 



49. Schematic representation of the central portion of the water-vascalar and peri- 

 liiçmal systems, together with the circular enterocœl and the axial sinus. The 

 radial water-vascular canals are wholly left out. 



ABBUEVIATIOXS. 



an. pro protoproct. 



brach, d ritflit br.icliiolari i arin. 



„ med median „ „ 



s kit 



can . aq pore cxnal . 



can. aren stone canal. 



cav. peiihaem perihsemal cavity. 



ent'e'I. n anterior enterocœl. 



,, cir circular „ 



, epiyfas epigastric „ 



„ p. d rii^ht posterior enterocœl. 



p. s left 



„ p'. s' secondary left posterior enterocœl. 



,, periœs periœsophageal enterocœl. 



oast stomach. 



int intestine 



sin. ax axial sinus. 



sin', ax' closed portion of the axial sinus. 



tent. dor. a anterior dorsal tentacle (= bipinnaria arm. 



„ „ p. posterior „ „ 



,, med. a anterior median „ 



,, „ p. ... posterior „ ,, 



., ven. a anterior ventral „ 



„ „ p posterior „ „ 



vas. nq. cir circular water-vascular canal. 



,, „ rad i-adial „ „ „ 



