NORTH AJIERICAN PORIFER^. PART IT. 535 



tabulate and lobed, with numerous closely approximate excurrent orifices on the flattened 

 uj^per sides of the lol^es, and central part of the mass. 



Loc, Florida, and Island of Noronha, Prov. Pernambuco, S. A., in Mus. Comp. Zoology. 



Variety excavata. This (PL xvii, figs. 10-11) differs from variety mollior in having a 

 slightly coarser texture with coarser px'imary fibres, but a similar smooth surface. The forms 

 are roiuided, and have numerous large, scattered, excurrent orifices. These lead into cor- 

 respondingly large canals which intersect each other in the interior, and give the whole mass 

 the appearance of being excavated or hollowed out. They are precisely similar to the 

 Australian form, Sj)ongelia rectillnea, but have a skeleton of finer texture, with less promi- 

 nent and more numerous primary fibres. 



Loc, Florida, in Mus. Comp. Zoology and in Soc. Coll., and La Paz, Lower California, 

 in Soc. Coll. 



Variety forammosa Hyatt. The form and the surface of this variety are altogether 

 pecidiar. The sponge is, in reality, made u]) of an aggregation of la^ge tubes radiating 

 towards the circumference, and divided by tolerably thick walls. The regularit}' of the 

 arrangement of these tubes and their increase in size outwardly, is the marked charac- 

 teristic. The texture is of medium fineness, with nearly parallel, and quite closely set 

 primary fibres in a specimen from Havana, in Coll. Mus. Comp. Zoology, in another, how- 

 ever, from Ft. Macon, in Yale Collection, the primary fibres are more widely separated, 

 and the tissue is altogether looser. The secondary system of canals is also very well devel- 

 oped, and the interior therefore resembles that of the preceding varieties, though not so 

 completely hollowed out. 



Spongelia cana Hyatt. 



This species has a remarkably white skeleton, although two of the three specimens 

 examined evidently were not entirely free from animal matter ; the exteriors are bleached 

 very white. The general plan of the mass is similar to that of Sponc/ia Mauritiana. Its 

 resemblance to this last, in fact, is comj^lete in form, aspect of the surfivce, and in the laby- 

 rinthine windings of the canals. The pi'imary fibres are regularly distributed, and the 

 secondary fibres connect them in a perfectly normal manner ; the size of the fibres and the 

 whole texture is as fine as that of any Spongelian yet observed. 



Variety cincta. This is precisely similar in every respect, except that the whole exterior 

 is covered by a thick layer of somewhat denser texture than the internal skeleton. This 

 gives the surface a remarkably smooth asj^ect, covering up all the marked inequalities, and 

 decreasing the size and number of excurrent orifices. The tissue of both varieties is sim- 

 ilar to, but considerably finer than, that of Spongelia excavata, which they resemble more 

 closely than any other species. 



Loc, Noronha, Prov. Pernambuco, S. A., in Coll. Mus. Comp. Zoology. 



Spongelia spinosa Hyatt. 



The exterior of this species (PI. xvi, fig. 3-3) is peculiarly rough or spinous, owing to 

 the projecting points of the primary fibres, which extend considerably beyond the surface. 

 The connecting tissue consists of a very irregular network of fibres. It is pierced by 

 excurrent orifices, and occasionally marked by a channel. This tissue resembles that of 

 Spongelia incerta. The absence of vertical tubes is also another similar characteristic; 



