3o8 SoiithcFu Cross. 



oe (I'sujiliagiis. 



oe. ill (i'soi)hageal invaijination. 



01' ovary. 



J), h. Ill parieto-basilar muscle. 



s '. siplionoglyph. 



r verruca?. 



(/ food yolk. 



1., 11., 111., IN' cycles of mesenteries or teutaclcs. 



Plate XLVIH. 

 Urticina sulcata. 



Fig. 1. — Reproduction from photograph of young female specimen (natural size), 

 hhowing invagination constriction and well-marked sulcation of body-wall above it. 



Fig. 2. — Transverse section of the sphincter muscle. 



Fig. 3. — Transverse section of one of the tentacles. 



Fig. 4. — Longitudinal section of a portion of the body-wall. 



Fig. 5. — Transverse section of mesentery near aboral end, showing the longi- 

 tudinal and ]iarieto-basilar muscles. 



Plate XLIX. 

 Urtieina carlgreni. 



Fig. 6. — Reproduction from ]ihotogra]ih (natural size) showing foreign bodies 

 still adherent to verruca?. 



Fig. 7. — Transverse section of sphincter muscle. 



Fig. 8. — Diagrammatic figure illustrating the arrangements of the cycles of 

 tentacles in relation \vith the intra- and inter-mesenteric spaces. Although the 

 tentacles are somewhat larger according to age, the difference in the diameter as 

 represented by the circles in the drawing is exaggerated. (The same arrangement 

 as here depicted pertains in U. sulcata also.) 



Fig. 9. — Longitudinal section of a portion of the body-wall. 



Fig. 10. — Transverse section of a fertile mesentery. 



Plate L. 

 Brood Chamber's and Embryos. 



Fig. 11. — Longitudinal or vertical section of body- wall of a specimen of U. carlgreni 

 ])as8ing through a brood chamber in an early stage of invagination and quite empty. 



Fig. 12. — Longitudinal or vertical section through the body-wall of a specimen 

 of U. rarh/reiti jtassing through the t'ljening to a brood chamlser of an older stage 

 than Fig. 11, containing a developing embryo and closed to the outside. 



Fig. 13. — Similar section through the sjiecimen of U. sulcata, figured (Fig. 1) with 

 brood chamber of a little earlier stage to Fig. 12. 



Plate LL 

 Brood Chambers and Embryos. 



Fig. 14. — Transverse or horizontal section of the same si^ecimen as Fig. 12 

 (U. carlgreni), passing through about the middle of the brood chamber. 



Fig. 15. — Similar section of the same individual, jjassing through the brood 

 chamber near its lower end, showing the prolongation of lobes of the chamber into 

 the mesenteric spaces. 



