140 N. AnnandalE: The Fauna of Brackish Ponds. [VOL. I, 



clubbed. The stem of the hydranths is obscurely annulated, their 

 bases are surrounded by loose sheaths of the perisarc. The distal 

 extremity of the filaments is free from the perisarc and contains 

 nematocysts in the ectoderm. The hydranths are spindle-shaped 

 and bear ten to fourteen capitate tentacles, which are arranged in 

 two distinct whorls. 



Gonosome — 



The medusae are borne only at the base of the inferior whorl 

 of tentacles on the hydranths ; they are minute, subquadrate in 

 transverse section, somewhat elongate, regularly and profusely 

 tuberculate externally, colourless. The manubrium is conical, 

 short, incapable of being extended as far as the opening of the 

 bell ; the velum extensive ; the four tentacles short and stout, 

 capitate, without swellings except at the extremities. (This des- 

 cription refers only to the young medusse before the appearance of 

 the gonads for the later stages have not been observed.) 



Fig. 2. — Young free gonosome of S. filamentata, highly magnified. 



I found only one example of this species ; it surrounded a grass- 

 stem at the edge of the pit in which the next form was also taken. 

 The spaces left vacant between the branches were filled by large 

 numbers of a gregarious Vorticellid Protozoon, the bases of the 

 individuals of which were inserted in a common covering of mucus 

 and sand grains. Numerous medusse were set free in a glass of 

 water in December and were kept under observation for two days, 

 at the end of which they died. Their manubria appeared to be 

 imperforate and their tentacles remained short and stout. They 

 moved through the water both vertically and horizontally by regular 

 pulsations of the bell. Some specimens were killed and preserved 

 in two per cent, formol ; they became longer in proportion to their 



