SILICIOUS AND HORNY SPONGES WILSON. 417 



In both genera the sponges are digitate, the processes generally 

 but not invariably slenderer in Chalinodendron than in Dactylo- 

 chalina. 



Lendenfeld later (1888, p. 102) modifies his earlier definition of 

 Chalinodendron, inserting the presence of conuli among the char- 

 acters. But the conuli are small, indeed must be very small in the 

 slenderer species. 



It seems to be advisable to combine the genera. Dactylochalina, so 

 understood, will even then probably run over into Paehychalina, but, 

 as is well known, Chalinine sponges are so "plastic" that their divi- 

 sion into genera is especially difficult. 



DACTYLOCHALINA EXIGUA (Lendenfeld), var. SAMARENSIS, new variety. 



Plate 42, fig. 1. 



Chalinodendron exignum Lendenfeld, 1887, p. 819. 



Three specimens from a coral reef near Catbalogan, Samar. 



Sponge consists of very many, long, slender, cylindrical, dichoto- 

 mously branching and freely anastomosing processes, 2-3 mm. thick 

 and reaching 150 mm. in length. These processes or " shoots " form a 

 loose mass 100-150 mm. in diameter. When such a mass is disen- 

 tangled it is found that anastomoses are so common as to give the 

 sponge a somewhat retiform appearance. Whether the primary 

 shoots which may be distinguished in such a mass were all originally 

 derived from a single basal one, can not be told. It is at least possible 

 that this is not the case but that branches of neighboring individuals 

 fuse indiscriminately with one another as well as with their sister- 

 branches. 



Sponge is slightly hard to the touch, but both compressible and 

 flexible, not rigid enough to stand erect in the air, but in nature per- 

 haps upheld by the water and waving about in it. Color now, whitish- 

 brown. 



Surface smooth, presenting, very distinctly with a lens, a reticu- 

 lated appearance, due to the large meshes of the dermal skeleton. 

 Sponge partially macerated. Oscula and pores? 



Skeletal reticulum composed of fibers 40-50 \>. thick, with large 

 meshes which very commonly are 300-500 £, but which range from 

 175 to GOO \l in width. In the ectosomal region, while there are very 

 many large meshes, small meshes are commoner than elsewhere. 

 From the axial part of the sponge main fibers curve upwards and out- 

 wards, becoming radial near the surface, where they frequently pro- 

 ject slightly. Between these there are transverse connectives. If the 

 section be taken through the axis of a stem, the skeleton shows con- 

 siderable regularity. All fibers, main and connectives, of about same 



