120 CEYLON PEARL OYSTER REPORT. 



Pasythea hexodon, Busk (10). 



There are some unbranched colonies of this species with from four to ten hydro- 

 thecae in a set, and with one or two gonothecae. 



The species is known from Australia. Our specimens were found growing on stems 

 of Iialicornaria insignis, &c, on the north of Cheval Paar, Gulf of Manaar. 



Family: II">1I1>.F.. 

 Idia pristis, Lamouroux. 



The largest piece of these specimens is broken off at the top. and is 3^ inches in 

 height. Gonothecae are present. 



This species is known from Torres Strait, Bahia, and the Persian Gulf. Our Ceylon 

 specimens were on worm tubes, &c, from oft' Galle, and onwards up the west coast 

 to Mount Lavinia and Kaltura, and also in the Gulf of Manaar. 



Family : PLUMULARIID.F. 



Plumularia setacea, Ellis. 



A good many colonies of this species were found, and gonothecae are present. 

 It was previously known from Australia, Messina, North America, and Britain. 

 Locality: Our Ceylon specimens were attached to worm tubes, &c, from the 

 north end of Cheval Paar, 7 to 10 fathoms, and elsewhere in the Gulf of Manaar. 



Plumularia buskii, Bale (11). 



There are a few colonies only of this form, about 1 inch in height, and without 

 gonothecae, but otherwise following Bale's description, excepting that, in some cases, 

 a few of the lower pinnae on the stems are opposite instead of alternate, an arrange- 

 ment that has been described in the case of Plumularia cornucopia, Hincks (16). 



The species is only known from Australia. Our Ceylon specimens were found in 

 the Gulf of Manaar. 



Monostaechas quadridens (McCrady) (18). 



The specimens of this form are about the size of those first described when Allman 

 founded the genus ; half an inch is the height of the largest colony. 



The species is known from Pacific reef, Barbadoes, and the North Atlantic. 

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



Antennella gracilis, Allman (3). 



These specimens agree with the description of Antennella gracilis in all respects 

 but size, and are probably from their position young colonies. They are about \ inch 

 instead of 1 inch in height. In the details of stems, hydrothecae and nematophores 

 they agree. The hydrothecae are not quite cylindrical, narrowing downwards 

 sligl itly. 



