432 COLLECTIONS FKOM MELANESIA. , 



the Indo-Pacific region, agrees well with the typical form of the 

 genus, only presenting its peculiarities, both external and internal, 

 under a decidedly more striking form than in the Atlantic and 

 Mediterranean species. Haliehondria infrequnns. Carter, differs from 

 it in having the spined acerate skeleton-spicule which occurs in 

 some of the Atlantic species, but agrees with it in having a biha- 

 mate ; its external characters are unknown, but it will almost 

 certainly prove to be a Crella. 



66. Crella schmidti. (Plate XLI. fig. a a.) 



Massive, sending up moderately thick lobes pierced by passages 

 1 to 4 millim. in diameter, lined by smooth surfaces bearing the 

 pores! General surface covered with narrow longitudinal ridges 

 about 1 millim. broad, 5 millim. high, and 1 millim. apart, rough ; 

 dermaljnembrane between ridges smooth, transparent. Vents few, 

 in depressions 1 to 3 millim. deep. Texture in spirit like crumb of 

 bread ; colour dirty yellowish white. Main skeleton somewhat irre- 

 gular, spiculo-fibre devoid of horny matter ; in deep parts spicules 

 1- or 2-serial, fibres very irregular in direction ; towards the periphery 

 primary fibres, with spicules 2- to 4-serial, run towards the surface, 

 generally at an obtuse angle to it ; they terminate between the 

 intermarginal chambers in tufts of the tibieUa spicule, 12 to 15 

 spicules broad, the distal ends of the tibielte spreading out upon the 

 dermal membrane and forming its only skeleton. Sarcode pale 

 brown, rather granular. Spicules : — (1) Skeleton acerate, smooth, 

 straight or slightly curved, tapering to sharp points from near 

 centre ; size -22 by -0063 millim. (2) TibieUa of dermal tufts, 

 straight, smooth, heads of same thickness as centre of shaft ; shaft 

 tapering to necks below heads, necks tapering gradually to the oval 

 heads ; size -22 by -0063 millim. (3) Equianchorate of flesh, tri- 

 dentate, the shaft stout, strongly curved; the teeth strong, well 

 curved inwards, sharp, the two lateral ones united to shaft by falcate 

 expansions ; length of spicule -037 millim., that of each head -013 

 millim., thickness of shaft -0044 millim. [(4) Bihamate of flesh, 

 contort, curve moderate, ends bent sharply inwards ; size -037 by 

 ■0021 millim. Possibly foreign to the sponge, but not uncommon 

 in both the deeper and superficial parts of the sarcode.] 



Hah. Port Jackson, 0-5 fnis. 



The only specimen is in spirit and well preserved, but small ; 

 the external characters peculiar to the genus are, however, well 

 marked. Whereas the head of the tibieUa is scarcely defined as 

 such in any of Schmidt's species (of which two are from the Adriatic 

 and two from the West-Indian seas), here it is quite a striking 

 feature of the dermal membrane when seen in section ; in Haliehon- 

 dria infrequens. Carter, above referred to, the head of the tibieUa is 

 similarly weU defined. The spicules are generally stouter than 

 those of Schmidt's species, and none of the skeleton forms are spined, 

 as appears to be the case in 0. elegans and papulosa, if not in hospi- 

 talis. I associate this species with the name of the distinguished 



