strobilization of aurelia 99 



List of Eeferences. 



1. Claus. — " Entw. d. Scyphistoma v. Cotylorhiza, Aurelia u. Chrysaora", 



' Arb. Zool. Inst. Wien ', vol. 10, 1892. 



2. Hein. — " Unters. iiber die Entwicklung v. Aurelia aurita ", ' Zeit. 



f. wiss. Zool.', vol. 67, 1900. 



3. Friederaann. — "Unters. iiber die postembryonale Entwicklung v. 



Aurelia aurita ", ibid., vol. 71, 1902. 



4. Heric. — " Zur Kenntnis der polydisken Strobilation v. Chrysaora", 



' Arb. Zool. Inst. Wien ', vol. 17, 1909. 



5. Gemmill. — " Notes on Food-capture and Ciliation in the Ephyrae of 



Aurelia ", ' Proc. Roy. Phys. Soc. Edin.', vol. 20, 1921. 



EXPLANATION OP PLATE 6. 



Fig. 1. — Longitudinal section of jjolydisc strobila showing relation 

 between gastral filaments and columella. 



Fig. 2. — Tangential section of base of strobila showing portion of solid 

 rod of ectoderm cells passing from oral surface to longitudinal muscle. 



Fig. 3. — Vertical section through interradius of newly liberated ephyra 

 showing base of manubrium, peristoniial pit, common base of gastral 

 filaments, and remnant of longitixdinal muscle. 



Fig. 4. — Vertical section through apex of newly separated ephyra showing 

 mesogloeal thickenmg and muscle remnants. 



Fig. 5. — ^Median vertical section through uppermost ephyra of polydisc 

 strobila. 



Fig. 6. — Flagellated cell from ectoderm of scyphistoma. 



Fig. 7. — Portion of living tentacle (a) extended, (b) contracted, showing 

 flagella and cells. 



Fig. 8. — Transverse section through connecting strand about half-way 

 along a polydisc strobila, showing cavity of muscle, and muscle fibres. 



Fig. 9. — Longitudinal section (somewhat oblique) cutting interradius 

 of two lowermost ephyra rudiments showing origin of manubrium. 



Fig. 10. — Longitudmal section (oblique) through interradius of strobila 

 showing relation between peristomial pit and longitudinal muscle of second 

 ephyra down. 



Fig. 11. — Longitudinal section through centre of third ephyra down 

 showing closure of apical opening. 



Fig. 12. — Three longitudinal section of lower ephyra rudiment in fig. 9 

 showing form of endodermal groove which provides lining of manubrium 

 {a) almost perradial, (b) about adradial, (c) near interradius and showing 

 commencement of abaxial rod of cells. 



H 2 



