118 CEYLON PEARL OYSTEE REPORT. 



Allmax (2), with which genus, however, this species has nothing else in common. 

 The species is known from Williamstown, Australia. 



Locality: The Ceylon specimens were attached to worm tubes, shells, algte, &c, 

 from the Cheval Paar, Gulf of Manaar. 



Sertularia loculosa, Busk (10). 



These specimens correspond with the description of the unbranched form in Balk's 

 catalogue, they are rather shorter and have no gonothecse present. 



Locality : This species, previously known from Australia, was found north of the 

 Cheval Paar, 7 to 10 fathoms, growing on the calcareous alga Halimeda. 



Sertularia rugosissima, n. sp. Plate II., fig. 4. 



Stems simple, rather less than \ an inch in height, of a bright brown colour. 

 Hydrotnecse, one pair to an internode, corrugated for the upper f of their length 

 (fig. 4). They touch in front, excepting the lower ones on the stem, and are 

 separated behind, and are free and divergent at right angles for \ their length. 

 They have two lateral teeth and are closed by a bivalve operculum. 



Gonosome not present. 



This is a neat, minute form, quite half as small as Sertularia pumila, and is the only 

 Sertularian with opposite annulated hydrothecse. - 



Locality : Found creeping over algge from the Gulf of Manaar. 



Diphasia mutulata (Busk), (10). Plate II., figs. 6 to 6b. 



This form corresponds entirely with Busk's descriptions. The pieces are only about 

 an inch in height, and are unbranched and bear male gonothecae (Plate II., fig. 6). 

 On some specimens the hydrothecse are smaller and less prominent than on others, 

 and sometimes subalternate (fig. 6b), and the gonothecae on these have only a few 

 spines near the top and are of smaller size. This form is shown on Plate II., fig. 6a. 

 The species has been found at Torres Strait and Port Molle, Australia. 



Locality : Our specimens were growing on stems of Lytocarpus, &c, at several 

 localities: off Galle ; Station I., off Negombo ; and in the Gulf of Manaar. 



Sertularella, sp. 

 A fragment of a Sertularella was found on the Cheval Paar, Gulf ol Manaar. 



Thuiaria, sp. 



Trophosome. Stems branched, about J of an inch in height, not fascicled, having 

 two, alternate, hydrothecse to an internode on the unbranched portion of the stem, and 

 where there is a branch, one hydrotheca is present also in its axil. Branches alternate, 

 with a joint shortly above their origin. 



Hydrothecse alternate, well separated, except near the tops of branches, where they 



