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BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 

 PHORTIS CEYLONENSIS (Browne) Mayer. 



Eirene ceyloncnsis Browne, 1905, p. 140, pi. 3, figs. 9-11. — Annandale, 

 1907, p. 79, pi. 2, fig. 7. 



Pkorlis ceyloncnsis — material examined. 



In the preserved condition the gelatinous substance is thin, the 

 bell very flat, and the long, narrow peduncle hangs far below its 

 opening much as Browne described it. But Annandale has found 

 that in life the bell is higher and more arched, its cavity deeper. 

 Neither of the specimens shows the complete number of tentacles in 

 any quadrant. But so far as I can judge by the portion of the mar- 

 gin still intact there must have been between 90 and 100 large ones ; 

 that is, just about the number recorded by Browne. There are also 

 a few young tentacles in various stages in development. There is 

 every reason to believe that ultimatel} 7 they would all attain the 

 adult condition. There are no cirri. 



Otocysts. — According to Browne there is one otocyst between 

 every two tentacles, and this is the general rule in the present ex- 

 amples. But there are some variations, there being sometimes two 

 otocysts, sometimes none, between two adjacent tentacles. On the 

 whole, however, there are about as many otocysts as there are tenta- 

 cles. In every otocyst which I have examined there is a single large 

 otolith, as Browne found was usually the case. But both he and An- 

 nandale have observed cases with two otoliths, due probably to 

 " twinning," as the otocysts in such instances are abnormally large. 

 In palhensis there are from 1 to 4 otoliths to each otocyst. 



Color. — Color, if any was present, has entirely faded in the pre- 

 served specimens. 



We owe to Annandale (1907) an account of the hydroid of this 

 species. This is closely alilecl to that of P. gibbosa, so far as I can 

 judge from the descriptions by Brooks (1883) and Annandale 

 (1907), but separable from it by differences in the form of hydro- 

 theca and gonotheca. 



The known range of ceylonensis extends from Ceylon to Lower 

 Bengal and to the Philippines. Annandale found it in fresh water. 

 P. palkensis is recorded from Ceylon and from the Nicobar Islands. 



