NORTH AMEEICAN PORIFEE.^. PART I. 401 



continuous fine ridges of that species. The skeleton, however, at once settles the question 

 of identity. It is composed of excessively coarse fibres, hollow, or more or less filled, as in 

 most parts, with layers of granular matter. These may be either concentric, and fill it up 

 more or less solidly, or only line the tube,' or, as in some instances, stretch as flat partitions 

 across a series of constrictions which cut up the tube into bead-like cavities. The reticulations 

 of the skeleton are of the simplest known form, being coarse, irregular and tree-like to the 

 last degree. The figure " represents the fibres which support a fistulose projection from a 

 colony, and it may be seen that the skeleton is but just sufficient to support the sarcode 

 and that no regular web or mesh is formed as in Aplj^sina. The ends of the fibres are free 

 and project considerably, causing the spiniform elevations of the surface described above, but 

 do not pierce the outer skin in carefully dried specimens. This is owing to the thick, tough 

 character of the cuticular layer which is not easily pierced. The sarcode itself in the inte- 

 rior is very abundant and solid, as seen in alcoholic specimens. Very minute spines were 

 occasionally seen attached to the surface of the cuticular layer, but the}' may have been ac- 

 cidental. 



Dendrospongia crassa Hyatt. 



Aplysina ceroj^hoba Schmidt (pars). Spong. d. Atlant. Gebiet., p. 30. 



A curious resemblance is produced between the exterior of dried specimens and Aplysina 

 cerophoha by the toughness of the external membrane. This forms ridges extending from 

 the apices of the branches and thus cuts up the surflice into more or less angular pits re- 

 sembling, though not so deep as, those due to the honeycomb-like cells of Aplysina. The 

 forms which I have seen maybe either fistular or irregularly shaped solid masses, with occa- 

 sional large excurrent openings. The color, according to Dr. Palmer, in nature is \exy dark, 

 almost black, and in alcohol it is dark purple. The fibres are of very large size and may be 

 followed in continuous lines for long distances. ^ 



Nassau, 12 feet, coi'al reef. Soc. Coll. 



Verongia Bow. 



Luffaria Duch. et Mich. 

 Luffar'm Schmidt. 



This genus was described by Bowerbank first in 1841 in the Annals and Magazine of Nat- 

 ural History, and subsequently in his British Spongiadte. He distinctly states that his type is 

 Spong ia fistular is Lam., an unmistakable sjjecies which is placed by Duch. et Mich, in their 

 genus Luffaria. This genus Schmidt adopts in his Spong. d. Atlant. Gebietes, thus suppress- 

 ing the name Yerongia which he had previously published as a synonym of Aplysina Nardo 

 in the Spongien d. Adriatischen Meeres, III Suppl., 18G6. The channels of the interior of 

 the fibres are very much smaller than in Aplysina and the anastomosis of the fibres occurs at 

 irregular intervals. The direction of the whole is determinable as a radiatory arrangement 

 but still the effect is that of a solid but excessively irregular net work. This is owing to the 

 fact that the growth of the fibres takes place over the whole exterior surfiice at once. 

 The frame work is formed by the simultaneous growth of projecting fibres over the 



IPI. 1.3, %. 1. api. 13, fig. 7. 



2 PI. 13, fig. 7. 



MEMOIKS BOST. SOC. NAT. HIST. VOL n. 101 



