222 CEYLON PEARL OYSTER REPORT. 



short and somewhat cluh-sh.-iped branches, about 25 millims. in length and 3 milliins. 

 in niaxinuini diameter, probably rose vertically upwards from repent stems of about 

 the same diameter. The surface is pretty uniformly covered with low conuli, between 

 which narrow longitudinal canals may be seen running beneath a thin membrane, 

 which is occasionally broken through by a single small vent or by a sieve-like group 

 of very small vents. The colour (in spirit) is very pale yellow and the texture pretty 

 stiff, but compressible and resilient. 



The skeleton (Plate XVI., fig. 3) consists of widely distant, longitudinal mum 

 fibres curving outwards towards the surface and connected at irregular intervals by 

 a round-meshed lattice work of secondaries. The main fibres are pretty regularly 

 cylindrical and about 0'12 millim. in diameter, not fascicled, and containing a good 

 many fragments of sponge-spicules. The connecting fibres are entirely free from 

 foreign matter ; they vary much in diameter, but are usually pretty stout. 



The canal-system is of the type usually met with amongst the Spongiidse. The small 

 flagellate chambers are approximately spherical and up to about 0'04 millim. in 

 diameter, with short, wide, exhalant canaliculi. The ground-substance bet-ween them 

 is finely granular. A very conspicuous histological feature is the presence of 

 numerous long, cylindrical cords of fibrous tissue running longitudinally through the 

 sponge. These cords are composed each of a compact mass of elongated, finely 

 granular cells, each with a very distinct, darkly staining nucleus. They closely resemble 

 the similar fibrous bands found in Euspongia, &c., and are probably contractile. 

 The characteristic Hircinia filaments are abundantly scattered through the soft 

 tissues. They are, however, very slender, and I have not succeeded in making out 

 the nature of their terminations. 



This appears to be a very distinct and well-characterised species, differing from 

 Hircinia dendroidea, SCHMIDT, which is, perhaps, its nearest ally, in its much more 

 slender branches and much more regular main fibres. I have much pleasure in 

 dedicating it to the zoologist to whom we chiefly owe our accurate knowledge of the 

 Spongiidse. 



R.N. 277 (deep water off Galle and onwards up West Coast of Ceylon). 



Hircinia anomala, n. sp. Plate XIV., fig. 5 ; Plate XVI., fig. 1. 



Sponge massive, irregular, with a tendency to become lobose or digitate. Surface 

 uniformly covered with small, sharp conuli, about 1 millim. in height and 2 millims. 

 apart ; with a minute reticulation of fine ridges chiefly radiating from the apices of 

 the conuli. Sometimes the surface reticulation is suppressed, and it may be present 

 or absent in different parts of the same specimen. The surface is not sandy, except 

 sometimes at the apices of the conuli. Vents inconspicuous, the sponge being, 

 perhaps, sometimes lipostomous. Pores scattered abundantly in the meshes of the 

 dermal reticulation. Colour (in spirit) varying from pale brown to black on the 

 surface ; pale brown internally. Consistence firm, but compressible and elastic. The 



