112 CEYLON PEARL OYSTER REPORT. 



Sub-order II. : THECAPHOKA. 



Family : HALECIIDiE. 

 Balecium, sp. 



There are only a few fragments of this interesting looking species with very widely 

 expanded hydrothecse. It looks somewhat like Diplocyaihus, Allman (4), hut is 

 without the nematophore-like cup characteristic of that genus. 



Locality : North of Cheval Paar, 7 to 10 fathoms. 



Halecium flexile, Allman (4). 



Several young colonies, only \ an inch in height, were found growing on the 

 oyster cages suspended from the side of the ship at Cheval Paar, in the Gulf of 

 Manaar. 



These colonies may seem too small to he referred to this species with certainty, 

 but they are evidently young, only here and there show the beginning of a fascicled 

 stem and have no gonophores present. The hydranths are very large and very 

 much swollen below the base of the tentacles. The specimens are beautifully 

 preserved, showing the details of internal structure clearly. The hydrophores do not 

 stand away from the internode so much as is shown in Allman's figures, but the 

 shallow annulation of the internodes is the same. 



Locality : This species was previously recorded from near Marion Island and from 

 Patagonia ; and the present specimens were found on oyster cages at the Cheval Paar, 

 in the Gulf of Manaar. 



Family: CAMPANULARIID/E. 



Clytia geniculata, n. sp. Plate III., figs. 4, 4a. 



Trophosome. Colony f of an inch in height. Stem bending slightly to right and 

 left, a hydrotheca on a ringed pedicel at each flexure, which has a decided kneedike 

 bend (Plate III., fig. 4). Stem monosiphonic, branched sparingly, a branch either 

 taking the place of a hydrotheca or being given off from the hydrothecal pedicel near 

 its base. Hydrothecse on long or short pedicels, ringed throughout, or only above 

 and below, with from 5 to 20 rings ; large and deep (fig. 4), with long 2-spined teeth, 

 and very compressible. 



Gonosome. Gonothecse cylindrical above, narrowing rapidly downwards, on short, 

 ringed stalks (fig. 4a), about 5 rings, and with a very short neck and wide rim to the 

 aperture, situated near the base of the pedicels of the hydrotheca? and containing 

 medusoid gonophores, the most advanced of which show 4 rudimentary tentacles. 



Locality : Growing on oyster cages suspended over the side of the ship, between 

 February 15 and March 10, on the north-east Cheval Paar, Gulf of Manaar. 



The peculiar mode of branching is the most striking feature of this form (Plate III., 

 fig. 4), one pedicel bearing a hydrotheca gives off another from its side which starts 



