22 ARTHUR DENDY. 



prefer to modify and extend their conception of the Cory- 

 morphinse so as to include Pelagohydra (as the authors 

 referred to include the Hybocodonidje and Monocaulidfe 

 of Allman) in preference to making a new family for its 

 reception. 



7. DESCRIPTION OF PLATES 1 & 2. 



Illustrating Professor Dendy's memoir on ^'Pelagohydra 



mirabilis." 



Explanation of Lettering. 



A.F. Annular fold of endodernri around the margin of the septum. B. T. 

 Branched tentacles. C. Can, Circular canal. Cnb. Cnidoblast. Cnp. 

 Cnidopod. D.F.C. Developing float cavities. Ecn. Endocodon of medusa 

 bud. Ect. Ectoderm. End. Endoderni. End. Bud. Buds of endoderm 

 growing into the mesogloea from the inner walls of the endodermal canals. 

 End. C. Endodermal canal. End. I. Endoderni of inner wall of endodermal 

 canal. End.L. Endodermal lamella of medusa. End.O. Endoderm of 

 outer wall of endodermal canal. E. U. E. Exumbrellar epithelium of medusa. 

 Fl. Eloat. G. C. Man. Gastral cavity in manubrium. L. G. B. Longi- 

 tudinal gastral ridges of endoderm. Man. Manubrium. Med. Medusae in 

 various stages of development. Mes. Mesogloea. M.F.Ect. Ectodermal 

 muscle-fibres. M. F. End. Endodermal muscle-fibres. Mo. Mouth. Nu. 

 Nucleus. Op. End. Openings of endodermal canals into gastral cavity. 

 Pr. Proboscis. jB. Can. Radial canals. Sep. Septum between the main 

 gastral cavity and the cavity of the float. S. M. T. Liternal supporting 

 membranes of the tentacles. St. Stolons. S. U. C. Subumbiellar cavity. 

 S.TJ.E. Subumbrellar epithelium of the medusa. S.U.M. Subumbrellar 

 muscular layer of the medusa. Sup. Mem. Supporting membranes of the 

 float. Syn. Vacuolated syncytium covering the supporting membranes of 

 the float. T. C. Thread-cells. Ten. Fl. Tentacles of float. Ten. Pr. 

 Tentacles of proboscis. Th. A. Thin area of wall of float around tentacle 

 base. w. The point where the ectoderm of the young medusa ruptures to 

 form the opening in the velum. x. Nucleus in syncytium apparently 

 dividing, y. Point of attachment of subumbrellar epithelio-muscular layer to 

 endodermal lamella, z. The place where the medusa was attached to the 

 stolon, 



