B. Special. 2. Demospongiae. J \ 



poral, lacunar, with narrow stomions. Oscula also with lacimar cribriporal chones, 

 narrow proctions open on the cloacal appendices. Stryphmi* ponderosus. 



Wide stomions numerous at certain points. -- Stryphnus mucronatus (-carbonariiis 

 and niger}. Stomions scattered, oscula open, generally on the summit of lobes. - 

 Thenea muricata. Equatorial inhalant zone and scattered lacunar afferent chones 

 with narrow stomions; eurypylous chambers; terminal osculum. - - Poecillastra 

 comprcssa. Oscula generally on opposite face to the pores, canals may be almost 

 straight from one side to the other. - - Craniella cranium. Stomions en crible. 

 Ectochones poraux, lacuneux, endochones pierce the fibrous layer, under the 

 rind are superficial cavities from which start the inhalant canals to branch into 

 the choanosome. The intracortical cavities of Sollas are probably irregular 

 ectochones. 



LendGnfeld(-) in Pachastrella ovisternata describes ellipsoid microrhabds and 

 some anomalous triaenes. 



Lendenfeld( 3 ) finds the sterraster of Placospongia monaxon; Keller therefore 

 rightly held the sponge a Monactinellid allied to the Spirastrellidae. 



Topsent() describes 16 new species (2 Tetractinellida, 11 Monaxouida, 1 

 Halisarca). - - Danvinella intermedia n. has horny spicules, triradiate only. 



Topsent ( 2 ) revises nomenclature employed by him in describing certain collections 

 some years since. A new Ectyonine genus. 



Topsent( 1 ) considers for the borderland between Monaxonida and Tetractinellida 

 Sollas's group Spintharophora the most happy yet suggested; the Axinellidae 

 should be removed and the name Hadromerina ( compact ) applied to the 

 remainder classified as in Bericht f. 1892 Porif. p 4. Halichondrina can then 

 be divided into: - - (1) Haploscleridae, with simple spiculatiou and diactinal 

 megascleres, =Chalininae ) Renierinae, Spongillinae, Gelliodinae, and Phloeodic- 

 tyinae ; (2) Poeciloscleridae, generally with chelae and monactinal mega- 

 scleres, = Esperellinae, Dendoricinae,Ectyoninae, and Bubarinae ; (3) Axinellidae. 

 Thus the Heterorrhaphidae disappear, being distributed to (1) and (2) respectively. 



Weltner ( ! ) describes specimens of Pachychalina compressa and Suberites Jicus . 



Letellier glued pins on to the surface of oyster-shells. When drawn away 

 each carried of fragment of nacre or calcaire, the traction required was found to 

 be 7 to 8 grammes per square millimetre: the tissues ofCliona round the oscula were 

 found to havea coefficient of rupture of 10 to 15 grammes, about 20 grammes 

 for the superficial tissues. Caoutchouc threads of 1 sq. mm. section were attached 

 to the surface and very gently twisted forwards and backwards ; in this manner 

 lunules were detached differing only in size from those found in the sponge 

 canals. Xacre is never pierced by the C. except perpendicular to its surface: this 

 is only explicable if the boring is mechanical. - Topsent 8 ) criticizes Letellier, 

 especially on the ground that the calcareous fragments detached by C. are of the 

 same size, and the same curious shape (with the surface of detachment rounded) 

 whether the part of the shell from which they come be soft and friable, or hard 

 and prismatic, the size depending on the diameter of the gallery. Le poli des 

 surfaces ne semble-t-il pas resulter plutot d'un decoupage conduit jusqu'au bout? 



Levinsen writes in Danish on microscleres of Desmacidonidae giving 

 drawings of chelae from Esperella, Myxilla, Clndorhiza, and Melonanchora . 



Wilson describes Esperella Jibrexilis n. The whole dermal membrane is pierced 

 with pores leading into numerous and spacious subdermal cavities ; spheroidal 

 flagellate chambers without special canals lie in thin sheets of tissue ( trabeculae ) 

 separating wide afferent and efferent canals. Tedania Brucei n. has round the 

 efferent canals much gelatinous tissue ; between are denser tracts, where only are 

 found flagellate chambers and a network of spicules. There are subdermal cavities; 



