DENDY—REPORT ON THE CALCAREOUS SPONGES 19 
Family Heteropiide Dendy. 
Flagellated chambers varying from elongated and radially arranged to spherical and 
irregularly scattered, with a distinct and continuous dermal cortex covering over the 
chamber layer and pierced by inhalant pores. Subgastral sagittal radiates and subdermal 
pseudosagittal triradiates present, with or without an articulate tubar skeleton. Nuclei 
of collared cells probably always apical. 
The term “pseudosagittal” is proposed by myself and Mr Row, in our forthcoming 
paper on the classification and phylogeny of the Calcarea, for the subdermal spicules of 
this family to distinguish them from ordinary sagittal triradiates, as we have come to the 
conclusion that the “basal” ray is not homologous in the two cases. We have discussed 
the nature of these spicules in the paper referred to. 
Genus GRANTESSA von Lendenfeld (emend.). 
Canal system syconoid. Dermal cortex without colossal longitudinally placed oxea. 
Section A. 
With large, usually radially arranged oxea, but without microxea. 
9. Grantessa hastifera (Row). 
(Plate 2, fig. 6.) 
Grantilla hastifera Row [1909]. 
I have found three specimens of this interesting sponge associated with Leucascus 
sinyplex amongst the branches of an Alcyonarian (Gorgonid) colony. 
The species was first described by Row from a single specimen from the Red Sea, but 
it is so well characterized that there can be no question of the specific identification. 
I cannot, however, agree with Row in referring it to his genus Grantilla. 
Row’s figure of the general anatomy as seen in transverse section is in the main 
correct; but the exhalant canals of the radial flagellate chambers are represented much 
too narrow, and the subgastral sagittal triradiates and subdermal pseudosagittal tri- 
radiates are represented of about the same size, while the subgastral spicules are really, 
on an average, a good deal stouter than the subdermal ones; moreover, the fine, hair-like 
oxea (trichoxea) which project from the dermal surface are omitted. 
The spiculation is as follows :— 
(1) Dermal triradiates; lying tangentially in the dermal cortex, as described and 
figured by Row. 
(2) Subdermal pseudosagittal triradiates, with the two oral rays considerably 
curved in a plane at right angles to the basal ray and thereby giving rise to deceptive 
appearances of inequality according to the point of view. 
(3) Subgastral sagittal triradiates, similar to, but typically stouter than the fore- 
going. The characteristic bending of the oral rays, in a plane parallel to the gastral 
surface, and the fact that they are of approximately equal length, are very clearly shown 
when the sponge wall is examined from the gastral surface as a transparent object. 
3—2 

