IIVDKOIDA. 117 



Gonosome. Gonothecse resemble closely those of Sertularia complexa, Clarke (13), 

 barrel-shaped and rugose, borne on the stems singly below hydrotheca? (fig. I b). 



Locality : Found growing on stems of other Hydroids and on the experimental 

 oyster cages in the Gulf of Manaar. 



I have seen no account or figure of anything corresponding with the peculiar 

 tongue-like process described above, except in Hincks' description (16) of the 

 contents of the nematophores of some Plumularians. In Diplocyathus, Allman (4), 

 ami Hypophyxis, Allman (4), we have other forms of Hydroids outside the 

 Plumulariidas which show nematophores, but in the present species there is no 

 containing receptacle for this process apart from the hydrotheca itself. The process 

 appears to reach from the centre of the stem and proceeds along the upper bent 

 portion of the hydrotheca. 



The orifice of this species is bilabiate, the upper surface slightly peaked, but when 

 the operculum is open it often appears to be even-rimmed and hooded. 



Sertularia fissa, n. sp. Plate II., figs. 2 to 2f. 



Trophosome. Colony a tangled mass of loose, straggling, rather coarse, brown 

 stems, about 3 inches in height, dichotomously branched (Plate II., fig. 2) ; both 

 stem and brandies bearing hydrotheca?, in opposite pairs widely separated from one 

 another (figs. 2d and 2f). Branches given off from before and behind a pair of 

 hydrotheesB, not from their sides; occasionally two branches coalesce, and there are 

 two pairs of hydrothecse found back to back (see figs. 2d, e, f). Hydrothecse 

 adherent for of their length, free above, and diverging at right angles with the 

 stem. They touch each other in front (fig. 2a), on the upper pairs, on the branches ; 

 but are separated below, and are widely apart at the back (fig. 2b). Margin with an 

 upper and 2 lateral teeth, often reduplicated, and having an operculum. 



GONOSOME. Gonothecae borne on stem and branches, attached just below a 

 hydrotheca (fig. 2c) by a short pedicel, and turned abruptly up to lie along the 

 branches. They are about 3 times the length of the hydrotheca?, oval, with a short, 

 broad neck and even rim, and strongly ribbed. 



Locality : Found on worm tubes from off Galle, off Mount Lavinia, off Kaltura, 

 and on the Cheval Paar, depths of from 6 to 30 fathoms. 



Sertularia tenuis, Balk (11). Plate II. , fig. 5. 



The present specimens agree with Bale's figures and description of the unbranched 

 form of Sertularia trams in size and shape of the hydrotheca? there are no gonothecae. 

 These colonies show the margin of the hvdrotheca? often reduplicated, and there is 

 a bivalved operculum. There is one colony which may be mentioned as possibly only 

 an abnormality in this species. It has a branch which proceeds from one of a pair 

 of the hydrothecse of the stem (see fig. 5), a feature of the genus Thecocladium, 



