208 THE MEDUSAE. 



Station 4694 ; surface ; 2 specimens, one 6X5 mm., the other very 

 immature, 3x2 mm. 



The number of tentacles in the different specimens is as follows : — 5 mm. 

 in diameter, sixteen tentacles, eight large (radial and interradial), eight 

 rudimentary, bulbular (PI. 42, fig. 3); 7x5 mm., twenty, of which nine 

 large and eleven bulbular (PL 42, fig. 4) ; 6x5 mm., seventeen, nine large 

 and eight small, of the latter several tentacular, others bulbular ; 3 X 2 mm., 

 eight, four large and four bulbular. The maximum observed both by Browne 

 (: 02) and by Maas (: 05) was sixteen, eight large and eight small ; Agassiz 

 and Mayer (: 02), however, have recorded a stage with thirty-two, eight 

 long, eight short, and sixteen bulbular. There is an ectodermic ocellus at 

 the base of every tentacle, and, as a rule, of every bulb ; but in one speci- 

 men these structures were lacking in several of the bulbs, and in the 

 youngest specimen they are present on the four large tentacles only. 

 Absence of ocelli on a bulb is therefore evidence of the recent origin of 

 the latter. 



In one specimen. Station 4605, diameter 5 mm., the radial canals are 

 somewhat jagged along their edges in their middle regions as they are de- 

 scribed by Maas (: 05) and by Agassiz and Mayer (: 02). In all the remain- 

 ing specimens the canals are smooth. 



The smallest specimen is of especial interest as being the youngest 

 individual of the species yet I'ecorded. In outline (PI. 42, fig. l) it differs 

 markedly from older specimens, the apical projection, which in the latter is 

 low and triangular, being long and rodlike, with a well-marked apical canal 

 running its entire length and terminating in a dilatation. The manubrium 

 is very short ; the lips as yet simple, though folded ; there are no traces of 

 gonads. Tentacles eight, four large radial, four bulbular interradial. Ocelli 

 present on the four large radial tentacles only. 



Color. — In life the manubrium, gonads, and tentacles are pink violet; 

 the ocelli are brownish red. 



Tiara papita has been recorded under its various names from New Guinea 

 (Lesson) ; the Indian Ocean (Eydoux et Souleyet) ; the Malaysian region 

 (Maas) ; near the Marquesas Islands (Agassiz and Mayer) ; Falkland Islands 

 (Browne). The present captures are from the Humboldt Current off the 

 west coast of Central America and from the neighborhood of Easter Island. 



