﻿IX, B, 3 Light: Dangerous Jellyfish in Philippine Waters 293 



United States, which is able to inflict a very severe and in some 

 cases dangerous sting. 



The large white or white and purple form common in Manila 

 Bay during the summer months is Lobonema mayeri Light, 

 which may prove to be identical with L. smithii of Mayer. 

 While able to inflict a very unpleasant sting, this medusa is 

 not dangerous. This species and the common black medusa, 

 Catostylus purpurus Mayer, which is harmless, belong to the 

 order Rhizostomae. 



Dactylometra may be recognized by its long ribbonlike oral 

 lappets and its numerous (24), slender, white, marginal ten- 

 tacles. Lobonema may be recognized by its large size, by its 

 long tapering tentaclelike marginal lappets, and by the long 

 slender filaments which hang down in large numbers from the 

 mouth arms. 



In Dactylometra which the Filipinos call fosforo the sting 

 is inflicted by nematocyst batteries in the 4 long ribbonlike 

 oral palps, in Lobonema which the Filipinos call lanterna it is 

 inflicted by the nematocysts of the long filaments which arise 

 from the mouth arms, and this medusa may be handled with 

 impunity if care is taken not to come in contact with these fila- 

 ments, while in Chiropsalmus the nematocysts are located in 

 the long marginal tentacles. 



Chiropsalmus quadrigatus may be recognized by its deep 

 transparent bell, about as high as thick and flattened laterally 

 in 4 planes, and by its very long slender tentacles banded 

 with lavender areas and arranged in 4 groups, typically 7 to 

 a group, each group arising from a stiff hand-shaped projection 

 of the exumbrella. The medusa reaches a diameter of 200 milli- 

 meters or more, with tentacles 1.5 meters in length. It is found 

 in shallow water, and is especially dangerous as its transparency 

 renders it very inconspicuous and it is apt not to be noticed by 

 the bather. 



The severe stings inflicted by this medusa are easily under- 

 stood when the tentacles are studied under the microscope. The 

 violet or lavender bands spoken of above are completely covered 

 on their outer surface with thousands of closely approximated, 

 slender, comparatively large, stinging thread cells or nema- 

 tocysts. A nematocyst consists in general of a capsule, the outer 

 end of which is extended to form a long hollow hair, which 

 usually bears on its outer surface recurved hooks or spines. 

 At rest, this hollow hair is introverted and lies coiled within 

 the capsule. 



