SKM.U:C>STH\I I .1: PELAQ] \. 



entoderm and these are quickly followed by another pair from the ectoderm of the throat- 

 tube, tlu- t\\n latter being <>o away t'rom the former. Tin- ectodermal pouches then give rise 

 each to two side branches and sunn thereafter the entodermal do the same. Thus the cen- 

 tral stomach comes to base 12 radial pouches. 4 more radial pouches are soon formed 

 from the ectodermal pouches, so that the voun; medusa finally possesses 16 radial pouches. 

 It follows ill adult medusa that the center of I he ex umbrella side of the central stomach is derived 

 from entoderm. 2 diametrically opposed, perradml pouches are ectodermal in origin and the 

 othei Z an i-ntodermal. The 4 imerradial pom IKS are ectodermal, and of the 8 adradial 

 pouches, 4 ;irc ectodermal and 4 entodermal. The wall of the cjesophagus is of ectodermal 

 "iMj.m. I he \oting medusa soon develops S lobes which bifurcate. omng 16 marginal lap- 

 pets. The 8 marginal sensc-oigans develop before the tentacles. The mouth is at first a sim- 

 ple, round opening ar the center of the crater-like ectodermal depression. It soon acquires 

 4 lips, but the mouth-arms do not develop until a later stage. It is probable that the ecto- 

 derm dms not take so large a share in the formation of the Stomach-pouches as Goette sup- 

 poses (see Chrysaora and Aurellia). 



Pelagia panopyra Pron and Lesueur. 



MfJma f>anop\ra, PERON- >T L>si M R, 1807, Voyage aux Torres Australia, planche 31, fig. 2. 



HI panof>\ra, PERON F.T 1 . ! i i , i ^09, Annal. du Mu^. Hist. N.U., tome 14. p. 349. ESCHSCHOLTZ, 1892, Syst. der Acal., 

 ,, I. if. 6, tii'. 2. -BnAM>r, lS',S, Mi'-in. AcaJ. St. Petersbmirg, tume 4, srr. 6, Sci. Nat., p. 382, taf. 14, fig. I; taf. 14 

 A. fii^n. 1-5.- -HAH k'KL, iSSo, Syst. tier Medusi-n, p. 509 (literature). VAKHOPFEN, 1888, Bibliotheca Zoologica, Heft. 3, 

 p. 14. Ff.WKrs, [SSj, American Naturalist, vol. 23, p. 592, fig. i; 1889, Bull. Essex Inst. Salem, vol. II, No. 7, p. 122, 

 plate <;, fig. i . MAAS, 1903, Scyphomeilusen iler Siboga ExpeJ., Monog. 1 1, p. 29. MAYKR, 1906, Bull. V. S. Fish Com- 

 mis-icm, \M!. ;;. |-.nt ;. p. 1 1 ;.). pl.itc- i, fig : .. ;, 4. BI..I i nw, II. K., i')O'), Mem. Museum Comp.Zool. at Hairard College, 

 \ >!. ". p. 4 ; .- \i \ \ , M/ -i. \M':, i n.ll. AL.t.L U'lvscn. Munclu-n, Suppl. BJ., i Abhandl. 8, p. 43. KISHINOUYE, 1910, 

 fnnriial Collrgr Sri. Tokvn, vol. zy. an. <j. p. '). 



The characters of this widely distributed Pacific form are described in the table under 

 the genus Pel<iin. It is distinguished from the closely allied P. flaveola by its pink colora- 

 tion, whereas P. fl<n-?olti is yellowish. Moreover the nettle-warts of P. panopyra are low 

 and domelike, while in P. flaveola they are erect and bluntly pointed. 



Fir,. ;f>4- -Pelagia favtola, from T.iMii. .ifrrr Agassiz and Mayer, in Mrm. 

 I ' 'up. Zool. at Harvard College. 



P. f>annf>\ra is common off the coast of California and extends across the Pacific to the 

 Malay Archipelago, and northward to Japan. 



Vanhoffen i\es the dimensions of a specimen as follows: Bel! 27 mm. wide, 6 mm. high; 

 month-tube 15 mm. long; lips i~ mm. long. 



\\ hen vouno the medusa has only 4 tentacles. When the bell is 15 mm. wide the gonads 



begin to develop. 



Pelagia panopyra var. placenta. 



Petunia placenta, HAVCKFI., iSSi . Mcdusen, p. 510. VANHOFFEN, 1888, Bibliotheca Zoologica, Bd. I, Heft. 3, p. n, 



laf. 6, fig. 20. 



This appears to be a very close variety of /'. p,iiir>f>\rn. Both medusa? are widely dis- 

 tributed over the tropical Pacific. See synoptic table of forms of Pi-la gi<i. I believe that this 



