REPORT ON THE MONAXONIDA. 5 



prominences resembling miniature cliains of peaked mountains, over and between which 

 it is glabrous ; (3) in having the skeleton less compact (this does not affect the tough, 

 compact character of the sponge, which in this case is not dependent on the skeleton 

 arrangement) ; (4) in having the ends of the spicules more commonly pointed, but still 

 roughened and irregular and very different from the long drawn out, sharply and evenly 

 pointed ends in Halichondria 2)cinicea. 



The specimen in question is 106 mm. in height by about 37 mm. in average 

 diameter. It bears several distinct, circular oscula, about 3 mm. in diameter. 



Locality. — Off Api, New Hebrides, 60 to 70 fathoms. One specimen. 



Halichondria 2)ellicidata, Ridley and Dendy (PI. I. figs. 1, la ; PI. II. fig. 9). 



1886. Halichondria pelliculata, Ridley and Dendy, Ann. and Mag. Nat. Hist., ser. 5, vol. xviii. 



p. 326. 



The single specimen in the collection (PL I. figs. 1, la) is erect, lobose, increasing 

 gradually in width from below upwards, and marked by a series of transverse grooves 

 and swellings into a number of segments, each of which probably represents a stage in 

 the growth of the sponge ; the top is flattened, and the sponge is just beginning to 

 branch into two lobes. In the middle of the flattened top there is a large compound 

 osculum, and a similar one occupies the end of the incipient branch (PI. I. fig. 1, o, o). 

 The height of the specimen is 62 mm., and the diameter at the top not quite 25 mm. 

 Colour in spirit yellow. Texture, internally soft and friable, but the surface is hard 

 and chitinous. Surface corrugated as above described, but smooth and glabrous. A 

 thin, hard, chitinous membrane covers the entire surface of the sponge, and appears to 

 take the place of the dermal membrane. Whether this is only a post-mortem condi- 

 tion or not, we are unable to say. Just below the surface are great numbers of round 

 or oval, highly granular bodies, about 0*3 mm. in diameter ; these may be the gland-ceUs 

 which secrete the chitinous envelope;-^ they occur in less numbers in the deeper parts of 

 the sponge. Oscula (PI. I. fig. 1, o, o) ; at the summit of the sponge is a single 

 large round opening, about 6 mm. in diameter, subdivided by a number of vertical 

 partitions which separate the diff'erent exhalent canals from one another ; a similar, 

 but smaller osculum occurs at the top of the incipient branch. 



Skeleton. — (a) Dermal; a very abundant reticulation of irregularly scattered, 

 horizontally placed, large oxeote spicules, (h) Main ; so far as we have been able to 

 ascertain this is rather sparse, not very regular, and with few distinct fibres, being com- 

 posed of large scattered oxeote spicules. It is, however, very difficult to obtain a satis- 

 factory vertical section, owing to the fragility of the internal tissues. In parts at any 

 rate the skeleton is rectangular in its arrangement, the fibres containing few spicules. 



1 For this very probable suggestion we are indebted to Dr. E. von Lendenfeld. 



