B. W. PRIEST ON THE CALCAREA. 105 



between tide marks on our coasts. It is sessile, massive, or coat- 

 ing ; surface lobular or crested, smooth. Cloacae numerous, 

 mouths simple, armed internally with very large and stout equi- 

 angular spiculated tri-radiate spicules, radii attenuated. 



Membrane of cloaca furnished abundantly with unicurvo-cruci- 

 form spicules. Oscula numerous, simple, dispersed over the sur- 

 faces of the cloaca?. Pores minute. Spicules of the skeleton equi- 

 angular tri-radiate, very variable in size and stoutness. Spicules of 

 interstitial and dermal membrane small, acerate, and minute 

 attenuato-spiculated tri-radiate spicules ; spicular ray short, basal 

 rays tri-podate. This species never attains to any great size, the 

 largest I have seen being one sent to me by my friend Mr. Hillier, 

 of Ilamsgate, and dredged off that coast ; it measures two inches 

 by one and a quarter. 



I now come to the third and last Family included in the order 

 Heteroccela, viz., the Teichonidce of Carter. 



I shall take Mr. Carter's description of Teichonella prolifera as 

 the example. This species simply consists of parenchymatous 

 structure, traversed by excretory canal systems, which, beginning 

 by small branches in the interior, terminate respectively by open 

 naked mouths at the surface, supported on a staple mass of small 

 radiates, accompanied more or less plentifully by very large ones, 

 which, from their much greater size, are rendered very conspicuous. 

 Thus we have no longer any cortical differentiation on the surface, 

 nor any cloacal cavity interiorly, but so far simplified structure that 

 it becomes identical with that of the common run of non-calcareous 

 sponges. 



In general appearance it is vallate, foliate, vertical, plicate, pro- 

 liferous. Pores invisible to the unassisted eye, scattered over the 

 surface thickly and generally. Vents slightly marginated, naked, 

 arranged more or less in single line along the margin only. 

 Spicules of two forms, tri-radiate and quadri-radiate, both of two 

 sizes. 



Mr. Carter, in his first description of this Family, included a 

 second species, viz., Teichonella labyrinthica, with the one just 

 described ; but on examining specimens of the same in the col- 

 lection sent to him by Mr. Wilson, of South Australia, he finds it 

 necessary to relegate it to the vicinity of Grantia compressa, still 

 retaining the specific name. 



I have now described as briefly as I could four of the species 



