CALCAREA. 25 



covered over by a continuous dermal cortex. The tubar skeleton is articulate, the first 

 joint being formed of chiactines. 



The above only differs from Dendy's definition of Sycettidse by the addition of the 

 words in italics. 



Streptoconus. 



Chiphorids in which the radial chambers are usually more or less united at places 

 where they come in contact with one another, and are always crowned at the distal 

 extremity with tufts of oxeote spicules. The tulmr skeleton is articulate, the first 

 joint being formed of chiactines. 



The definition of this new genus in the Chip/ioridae corresponds to that of S>/co7i 

 in the Sycettidse. 



Streptoconus australis. 



(Plate XXVII., Fig. 3, and Plates XXXII. and XXXIIL, Figs. 75-80.) 



There are three specimens of this new species in the collection ; all are small, 

 shaped like a Florence flask and covered with long projecting oxea, see Fig. 3. They 

 are white as preserved in spirits. 



Their dimensions are between 7 ram. x 3 mm. and 10 mm. x 4 mm. 



Tlic gastral cavity terminates in a long oscular collar 2 mm. to 3 mm. long, 

 with slightly everted edge crowned with a fringe of slender hastate oxea. 



The l)ody wall is made up of the radial flagellated chambers (see Fig. 75 ), which 

 touch each other for most of their length and have large projecting distal cones 

 crowned by tufts of long slightly l)ent hastate oxea ; these oxea converge in cones over 

 the chambers, and then, crossing spirally, spread out and interlace. Each chamber 

 opens separately into the gastral cavity. In tangential section the chambers appear 

 more or less renularlv arranjred as hexagons with triansfular intercanals. 



The Skeleton. — The whole gastral cavity and oscular tube is lined with a sparse 

 layer of large (juadriradiates (see Figs. 77 and 79), regulai'ly arranged with the basal 

 ray pointing downwards and the apical ray projecting into the gastral cavity ; the apical 

 ray is slightly bent orally. A few of these large radiates appear to lack the apical ray. 



The radial cliambers have articulated skeletons (see Fig. 75), the proximal joint 

 consisting of chiactines, all of which have their apical rays turned towards the 

 flagellated chamber, so that when looking at the gastral surface the apical rays appear 

 to form a protection to the apopyle (see Fig. 79). The upper joints of the articulated 

 skeleton of the flagellated chamber consist of triradiates of ordinary form. The 

 unpaired rays of the outermost triradiates project, with the oxea, forming the bases 

 of the large distal tufts. 



The oscular collar has a very fragile skelett)n consisting of large quadriradiates 

 widely spaced (see Fig. 77). On the outside it is thinly covered with long 

 oxea which project downwards and outwards at an angle of about 45° from the axis. 



2 L 2 



