208 PROCEEDINGS OF THE ACADEMY OF [1887. 



Fusiform spicule short, thick and smooth fundamentally, averaging 

 10 by l-6000th.inchin its greatest dimensions, but variable in length, 

 presenting one to twelve spines most whimsically scattered over 

 the surface, so that no two spicules are alike in this respect. 

 Aperture of the statoblast single, circular, slightly marginated, 

 about eo'ffoths. inch in diameter. 



Skeletal spicule slightly curved, smooth and gradually pointed 

 comparatively small, forming, by overlapping each other linearly, 

 the thread-like bundles mentioned ; about 40 by l-6000ths. inch in its 

 greatest dimensions. 



Dermal layer and tissue generall}^ abundantly charged with 

 minute birotulates, almost identical with those of Meyenla everetti, 

 but a little larger and with longer and more recurved teeth at the 

 terminations: about e^^ooths. inch in length." 



Log. Heart's Content, Avalon Peninsula, ^Newfoundland. 



All the specimens of this sponge came from the neighborhood of 

 Heart's Content, but whether they were gathered from a lake upon 

 the heights or from a brook, mentioned by Mr. Mackay, near the sea 

 level, does not seem entirely clear. The accompanying illustration, 

 magnified 225 diameters will suggest the peculiarities of its skeleton 

 (crossed below), dermal (at lower corners) and gemmular spiculation 

 (above). The striking resemblance (alluded to by Mr. Carter), of 

 the dermal spicules to the minute birotulates, heretofore only known 

 in a corresponding position, in the cases of Meyenla everetti and 

 Spongilla hdhnii, will at once impress the student. These are how- 

 ever more variable in size, are occasionally s^^ined, and have their 

 rays more prolonged and more delicately terminated. 



It is in the singular character of the spicules surrounding the 

 gemmules that this species must attract peculiar attention. As the 

 reader must already have discovered, the six genera included in 

 Carter's system may be divided into two principal groups ; one of 

 them including only the genus Spongilla, characterized by the linear, 

 acerate spicules surrounding the gemmules; and the other, comprising 

 all the other genera, where the spicule of corresponding significance 

 is a birotulate or some easily recognized derivative of that type. 

 Within this latter and larger group, intermediate forms, connecting 

 the defined genera, are frequent, and the location of species upon 

 one side or other of the distinctive line, comparatively unimportant. 

 Heretofore, between the genus Spongilla and those genera comprised 

 in the other group there has been "a great gulf fixed." One only 



