516 HYATT'S REVISION OF THE 



surface is covered in part by fringes having the branching form of those figured by Du- 

 chaissing and Michelloti, as cliaracteristic of this species. There are also two other speci- 

 mens which exhibit a similar surface from the same locality, one of them a young colony 

 with a smoother surface and somewhat softer than is usual in lai^ge specimens. 



Variety Ilawaiianensis. One specimen from Hawaii, West Coast, exhibits the peculiar 

 surface of this species, and its characteristic skeletal structure, but is much coarser than any 



other form. 



Spongia graminea Hyatt. 



This (PI. XV, fig. 2) is one of the " Grass sponges " of commerce, and is perhaps one of 

 the least variable of all the species. The general description given by Duchaissuig and 

 Michelloti for Spongia iitilis, might at first sight appear to apply to this sponge, as it might 

 indeed to almost any of the group ; but there is one remark which enables me to deter- 

 mine the question of identity. " Des oscules superficiels tres-nombreux et ayant a peine 

 une ligne se presentent sur tons les points de la surface superieure, mais cependant de pre- 

 ference sur les parties les plus saillantes." This last word is decisive, since m this sponge 

 the situation of the apertures in the depressions between the lobes or ridges is esj)ecially 

 constant and characteristic. 



The general texture is coarser than in variety tubuUfera, and the interior is exceedingly 

 open, owing to the large size and central situation of the elFerent canals. The form is that 

 of a truncated cone, fluted by deep furrows on the sides, and either infundibuliform or flat 

 on the truncated surface. The large excurrent orifices are all upon this surface, or in 

 the depression which takes its place. The smaller apertures are situated on the sides, 

 invariably in the depressions between the ridges. The persistency of the form and 

 of the lateral ridges and the situation of the different kinds of orifices, are by far the most 

 characteristic features of this species. Notwithstandmg these facts, and though I am 

 obliged to describe this, and some other forms, as distinct species, I have great doubts of 

 the truth of the assumption. It rests upon the evidence of many specimens, but they are 

 all from one locality. It is very likely that this and Sjjonrjia discus, and perhaps even 

 Spongia lignea, will be found to have intermediate forms. I have also recognized indica- 

 tions of an approximation to sub-species corlosia, but the material at my command is not 

 abundant enough to settle these questions satisfactorily. 



This species has very singular fibres in the skeleton. The primary and secondary are of 

 nearly equal size and very light colored in a cured skeleton. The mesh is irregular in 

 shape. Even the secondary fibres were not free from debris in the specimen examined, 

 and in some parts of the same it was impossible on account of the absence of the usual 

 core of debris to pick out the vertical fibres. 



It is reported to be very abundant by Dr. Palmer, growing on reefs, and generally asso- 

 ciated in considerable numbers. They may grow on smooth bottoms, or attached to 

 corals or to other sponges ; a somewhat remarkable peculiarity. The color is black in the 

 living. Those in our collection were foimd in three feet of water. There is one about 

 seven inches in height to about five and a half inches in diameter, but they are said to 

 grow to twice that size in deeper waters. 



Locality, Key West. Habitat, reef three feet and deeper. Soc. Coll. 



