288 



DISCOVERY REPORTS 



apex, but in Boiigainvillia macloviana young tentacles may also develop among the 

 older ones, causing an overcrowding vi^hich results in a displacement of the tentacles, 

 so that they become arranged in two rows, both of which contain old as well as young 

 tentacles. In some of the largest bulbs, the rows become irregular in places and the 

 tentacles three deep. The maximum number of tentacles counted on one bulb was 

 sixty-six, but the more usual number for mature adults is about forty to fifty-five. 



There is a large round or crescent-shaped black ocellus at the base of every tentacle. 

 The ocellus is not on the tentacle itself, as in most other species of Boiigainvillia, but 

 on the basal bulb, and where two rows of tentacles exist the ocelli belonging to the outer 

 row are squeezed forward and are situated on little projections. A few of the ocelli have 

 particles of black pigment scattered around them and occasionally arranged in a circle. 



The maximum number of tentacles in one basal bulb in some of the larger specimens 

 was as follows : 



Family PANDEIDAE 

 Genus Halitholus Hartlaub (1914) 



Generic characters. Pandeidae with a large gelatinous apical projection; with 

 numerous tentacles (eight or more). Manubrium with a broad, cross-shaped base; the 

 longitudinal, perradial edges of the manubrium free, not connected with the radial 

 canals by mesenteries. Gonads forming eight adradial rows of transversal folds, some- 

 times connected interradially by a horseshoe-shaped fold. Mouth rim slightly folded. 

 Radial canals with almost smooth edges. Tentacle bulbs with or without an abaxial 

 ocellus. 



The genus Halitholus is distinguished from Leuckartiara and Neoturris by the com- 

 plete absence of mesenteries connecting the upper parts of the perradial edges of the 

 manubrium with the radial canals. 



Halitholus intermedius (Browne) (Plate XIV, fig. 7; Plate XVI, figs. 1-2). 

 Tiara intermedia Browne, 1902, p. 277. 

 Specific characters. Adult: Umbrella bell-shaped, little broader than high, with a 

 large conical crown. Manubrium broad and massive, cross-shaped in transverse 

 section ; about half to two-thirds the length of the umbrella cavity. Mouth large, with 

 four lips and the margin slightly folded. Gonads on the sides of the perradial lobes of 



