526 ' HYATT'S REVISION OF THE 



Variety nerjligens. The Key "West specimen (PI. XYii, fig. 4) of this variet}^ is so caver- 

 nous that it resembles an irregular roll or bundle of anastomosing branches. The surface 

 is smooth, but the skeletal structure is very similar to that of variety " vermiculatiformis." 



The Nassau s^^ecimens (PI. xvii, fig. 2) are more solid, and exhibit large oscules ■which are 

 absent in the preceding. They are also very cavernous, but the epidermis of the mass 

 when living evidently covered all the internal inequalities caused by the channels. This 

 variety may possibly, and in fact the Avhole species may be in part the Caccospongia 

 mollior Schmidt. 



Variety papyracea. A specimen labelled " East Indies," from the Collection of Yale 

 Museum, has a dendritic form, but otherwise, in texture of skeleton and general aspect of 

 the fibres and their arrangement, it resembles variety "neglicjens." 



Sub-species mollicula. 



There are very interesting specimens of this form from Zanzibar, Coll. Peabody Acad- 

 emy of Science, and Aspinwall, Yale Coll. The fibre is of the softest and finest description. 

 The mass is also much denser than in variety negUgens, and the texture excessively 

 irregular. It is quite possible that this variety may turn out to be a distinct species. 

 The surface is very similar to the smoothest and densest varieties of sub-sjoecies hibuUfera. 

 The interior is not at all cavernous, and the surface is very irregularly seamed by crooked 

 channels and pitted with oscula of small size. 



Sub-species Cookii. 



Specimens of the typical variety of Cookii have the surfiice covered by coarse tufts, 

 and in the same specimens the fibres differ greatly in size, being in some parts very 

 coarse and in others very fine. The color also varies from light yellowish brown to dark 

 red. The dried skeleton is harsh, but elastic and not easily broken by pressure, though 

 very readily torn apart, differing in this respect very much from the typical Spongia?. 



Loc, Zanzibar, in Coll. Peabody Academy, and Soc. Coll. Collected by Mr. Caleb Cook, 

 of Salem. 



Variety ditelliformis . The general texture appears to resemble that of Cookii. The 

 number and arrangement of the canals, their iiTegularity, and the complete manner in 

 which the interior was honeycombed by them, together with the veil, are, however charac- 

 teristic, altogether distinct. There is also a complete absence in all parts of any primary 

 fibres properly so called, the whole texture being typically Spongian. The veil is composed 

 of the internal fibres, which are deflected and closely interwoven in the same plane, bridg- 

 ing over larger internal openings and canals, and reducing the apertures to a very small 

 size. This specimen shows that the Ditelian veil may in its most complete form be pos- 

 sessed by true Spongia as well as by Spongelia and other genera. 



Loc, Island of Fernando Noronha, in Coll. Mus. Comp. Zool. 



Variety tectoria. This variety is dvendritic in the two specimens which were examined. 

 The internal texture was similar in every respect to that of the preceding variety, but the 

 veil was the marked characteristic. It extends over the whole surface, and the mesh is 

 circular or cellular, very much smaller than in the interior, and composed of much finer 

 threads, here and there underlaid by the coarser fibres of the interior. 



Loc, Pacific, U. S. Ex. Exp., hi Yale Coll., and Coll. Mus. Comp. Zool. 



