EBPEBEI.LA. 213 



Esperella serpens, n. sp. 



The sponge consists of a reticulation of branched and often anastomosing 

 cylindrical and digitate parts, which have an average thickness of 4 millim., 

 and which form an irregular horizontally expanded cake-shaped structure, 

 attached by a broad base. 



The skeleton consists of longitudinal spicule-bundles which are on an average 

 0*03 millim. thick, 0'15 millim. apart, and connected by single spicules. 

 Besides these there are spicules scattered irregulai'ly in the ground-substance. 

 All the sjncules are uniform in shape : styli, 0-22 millim. long and O'OOS 

 millim. thick. They are cylindrical in the centre, and very abruptly pointed 

 at the sharp end. Towards the blunt end they taper slightly to an incon- 

 spicuous constriction which divides the somewhat knob-shaped blunt end from 

 the body of the spicule. Li the ground-substance microsclera of two kinds are 

 found: — 1, sigmata ; 2, chelae. The sigmata are simple curves with abruptly 

 bent, pointed ends, clasp-shaped, 0*02 millim. long, and pretty scarce ; the 

 chelae are anisochelae, 0"018 millim. long, and the curved palmate portion on 

 one end is about twice as long as that on the other. 



G-EOGEAPHiCAL DISTRIBUTION. — East coast of Australia : Port Jackson, 



N. S. W. (LendenfeM). 



Esperella penicillium, n. sp. 



The sponge is composed of anastomosing branches, on an average 7 millim. 

 thick. The surface is covered with small, sharp, and slender projections 

 which stand very close. The oscula are scattered, 2 millim. wide. Alive the 

 sponge is of a deep orange-yellow colour. 



The slcehton consists of a network of spicule-bundles, which extend upwards, 

 are fi*equently branched, and form numerous anastomoses, so that longitu- 

 dinally disposed elongate meshes are formed. There are no transverse con- 

 necting-fibres, nor many spicules scattered in the ground-substance. The 

 spicules forming the fibres of the supporting skeleton are styli and strongyla, 

 0-35 millim. long and 0-006 millim. thick. The two ends of the strongyla are 

 equal and similar to the blunt end of the much less frequent styli, which 

 occur only exceptionally, and have an abruptly pointed sharp end. These 

 spicules are straight, or rarely slightly curved, cylindrical in the centre and 

 tapering slightly towards the blunt end, which consists of a slight thick- 

 ening, and appears somewhat knob-shaped. There are microsclera of two 

 kinds — sigmata and chelae. The sigmata are pretty rare, their ends are 

 unequal or equal, inasmuch as both or only one may be abruptly recurved and 

 sharp-pointed. They are 0*045 millim. long. The chelae are anisochelae, 0*033 



