TRACHYMEDUS^E — PERSA. 



407 



derm of their axial cores within the gelatinous substance of the bell. There was only one inter- 

 radial, naked lithocyst-club. The velum was very wide. The manubrium lacked a peduncle, 

 due probably to immaturity. There were 4 lanceolate nematocyst-studded lips. The 8 straight, 

 very narrow radial-canals were perradial and interradial in reference to the lips. The 2 

 small, immature, vesicular gonads were perradial, 180 apart, and at the middle points of two 

 diametrically opposed radial-canals. 



260. 



Fig. 259. — Persa lucerna, after Haeckel, in 

 Syst. der Medusen. 



Fig. 260. — Persa,sp. Young medusa. From 

 life, by the author. Naples Zoological 

 Station, Dec. 11, 1907. Showing an en- 

 larged view of one of the marginal sense- 

 clubs. 



Synopsis 0} the Described Forms of Persa. 



P. incolorata, McCrady. 



Size of bell in mm. 

 Shape of bell. 



Number of tentacles. 



Number of lithocyst-clubs. 



Length of peduncle in terms 

 of bell-radius (r). 



Form of stomach. 



Shape and size of gonads. 

 Color. 



Where found. 



2 high, 1.2 wide. 

 Bell-shaped. 



60 to 80 



8 



One-third r — . 



Cylindrical, with 4 lanceolate 

 lips. Stomach long. 



Sausage-shaped, r+ long. 



Colorless. 



Coast of North and South 

 Carolina, United States. 



P. lucerna Haeckel,* 1879, Syst. 

 der Medusen, p. 278, taf. 16, 

 figs. 12, 13. 



2 high, 2 wide. 



Octagonal and prismatic below, 

 pyramidal, with hemispherical 

 apex above. 



40 to 60 



8 



0.5 r, conical. 



Cylindrical, r long, with 4 long, 

 lanceolate lips. 



As in P. incolorata. 



Haeckel calls it colorless. A liv- 

 ing specimen studied by me at 

 Naples had a ruby-red spot in 

 the entoderm above the origins 

 of 16 of its 46 tentacles. 



Corfu, Mediterranean. Common. 



P. dissogonima Haeckel,* 

 1879, p. 279. 



3 high, 2 wide. 



Lower half cylindrical, upper 

 hemispherical, with small 

 hemispherical apex. 



32 



One-third r — . 



As in P. lucerna, but with 

 wide, short lips. 



As in P. incolorata. 



Colorless. 



Algeciras, Strait of Gibraltar 

 Rare. 



*Haeckel's so-called "species" are probably identical with P. incolorata, McCrady. 



