614 



MEDUSiE OF THK AVOHLI). 



entlv under the impression that it was identical with P. ornata Brandt, (rom the Pacific, hut 

 Haeckel rightl\- distinguished it as a distinct species. 



The iollowing description is hased upon mv study of a single good specimen of this medusa 

 collected by Dr. S. Lobianco at Naples, Italy, on January ii, 1901, and now prcscr\cd in 

 formalin at the Naples Zoological Station. 



Disk 155 mm. in diameter, flatter than a hemisphere, being only 55 mm. high. Exum- 

 brella surface fineh' granular, being covered with small, thickly clustered nematoc\st-warts. 

 16 marginal sense-organs, 4 perradial, 4 interradial, and 8 adradial. Sense-organs set at 

 bottom of deep, narrow clefts in bell-margin. The sense-club has no ocellus, merely a terminal 

 mass of entodermal concretions. No sensory pit in exumbrella above the sense-club. 32 

 narrow, rhopalar lappets are separated b}' shallow clefts from the 16 wide, velar, simple lappets. 



Fig. 392. — Phacellophora sicultiy tlr.iwn by the .luthur, from a specimen found at Naples by 

 Dr. S. Lobianco, January ii, 1901. B, enlarged view of part of one of the tentacles. 



The tentacles are arranged in 16 clusters and arise in a single row from the inwardly- 

 arched outer margin of the ring-canal, on the subumbrelia side ot the 16 velar lappets. Each 

 cluster consists of about 9 to 15 tentacles. In the Naples specimen these tentacles are about 

 half (75 mm.) as long as diameter of disk and are set inward at a maximum distance of 17.5 

 mm. from the bell-margin. A narrow canal extends throughout the length of each tentacle 

 on the inner (centripetal) side to its tip. A double row ot mammilorm, nematoc\st-bearing 

 papillae extends along the inner side of each tentacle close to the tentacular canal, which sends 

 off lateral diverticula into the papillx. The outer (centrifugal) side of each tentacle is pro- 

 vided with circular muscle-fibers, which are interrupted along the line of the papillae. 



