THE BODY-CAVITIES OF THE STAR-FISH. 



83 



may be shown by the adjoined cuts, in which the four smaller squares represent 

 the four portions of the larval enterocœl. The broken linos represent the parti- 

 tions, real or imaginary, that obtain in the larva, and full lines the partitions 

 that obtain in the adult. The names of the different cavities are written within 

 the parts of the larval enterocœl from which they arise. 



Posterior. Posterior. 



Ectt. |jer£<Rs.|' \^ e 

 Sa«. (Loy. < \ c?ç 



X s * 





■! K- s '■ \ 



Xjctro Gil 



1 



1 

 1 





i'ctr. 

 1 



Si n<. 



1 



! ax 



Ent. /* 

 S<vc. (Lor. 



erioes 



Evv,t. iOir. \j>, 



Cbivr. |>|er<.V>«eT^ fra 



Hydro ccel . j 



Si 



ttV.I CLJt . 



Anterior. 



Asterias pallida. 



Eut. perices 



Ent. cir 



Ent. epigast 



Ent.p's' 



Cav. perihrem part. .. 

 Sin. ax 



Anterior. 



Asterina gibbosa. 



Periesophageal enterocœl 

 Circular enterocœl. 

 Epigastric enterocœl. 

 Secondary left pos'erior enterocœl. 

 Periha?mal cavitieä partly. 

 Axial sinus. 



on 



It may be added that this diagram may be directly derive! from nature by 

 viewing the larva from the ventral side and supposing the body to be cut open 

 in the dorsal mid-line and spread out flat, and imagining the larval enterocœls as 

 squares. 



LITERATURE CITED. 



1) Goto, S. — The Metamorphosis of Asterias paUidi, wit Special Reference to the Fate of the 



Body-cavities Journ. Coll. Sci , Imp. Univ., Tokyo. Vol. X, Pt. HI. '93. 



2) MacBride, E. W.— The Development of Asterina gibbosa. Quart, Journ Mie. Sci. Vol. 38, 



Pt. III. '95. 



3) Bury, H.— The Metamorphosis of Echinoderms. Quart. Journ. Mie. Sci. Vol. 38, Pt. I. 



95. 



4) Ludwig, H. — Entwicklungsgeschichte der Asterina gibbosa Forbes. Zeitsch. f. wiss. Zool. 



Bd. 37. '82. 



Printed September 30th, 180S. 



