Plaie XXIII. 



Asterias pallida (Ag.). 

 'àl. i'îinisagittal section of a star slightly prior to stage H ; 7 sections (eacli=G-7 

 // ) oil the right side of tlie next, x 153, 



38. Sagittal section of ditto, x 153. The small cavity lying between the closed 

 portion of the axial sinus (siii. a.c.) and the periœsophageal enterocœl (ou the 

 left side of the figure) and connected with the latter by a solid string of cells is 

 probably an accidental occurrence. 



39. Frontal section of a star in stage H. x 135. 



40. One of a series of sagittal sections of a transforming larva in a stage between F 

 and G ; to show the atrophy of the protoproct. Cf. Fig. 32. x 153. 



41. Madreporic portion of a radial section of a star whose E=40 mm. x CO. 



ASTROPECTEN BISPINOSUS, M. T. 



42. Portion of a radial section directly under the madreporite ; R --G5 mm. x 50. 



A.STERIAS TENERA, StIMPS. 



43. Madreporic portion of a radial section of a specimen whose R=1G mm. x 00. 



ABBREVIATIONS. 



an . pro 25i'ot'->pi'öch 



brach, d riglit br;icliiolari\ arm. 



„ med median ,, „ 



„ s left 



can. aq pore canal. 



can. aren stone canal. 



cav. perihsem perih£emal cavity. 



ent'c'I. a anterior enterocœl. 



,, cir circular „ 



„ epigas epi<^-astric „ 



„ p. d right posterior euttrocœl. 



p. s left 



„ p'. s' s coudary left posterior enterocœl. 



„ periœs periœsophageal. 



gast stomach. 



i ut in testi ne. 



siu. nx axial sinus. 



sin', -.ix closed portion of tlie iixial sinus. 



tent. dor. a anterior durs.il tentacle (= bipinnaria arm.) 



,, p posterior ,, „ 



,, med. a. ... nnterior median „ 



„ p posterior „ ,, 



„ veil, a, anterior ventral „ 



„ „ p posterior „ „ 



vas. aq. cir circular water-vascular canal. 



„ ., rad i-adiil 



