HYALONEMA (LEPTONEMA) CAMPANULA. 245 



ha\ing no smaller kind of macramphidiscs, no mesamphidiscs, and no spheres, 

 and by the distal ray of its pinules being more slender, and its microhexactines 

 much larger. Although these differences are very conspicuous and quite suffi- 

 cient for specific distinction, there is a considerable degree of similarity between 

 the two. 



LEPTONEMA, subgen. nov. 



Species of Hyalonema the amphidiscs of which have hyperbolic, hemispheri- 

 cal, or bell-shaped terminal anchors about one fourth to one third of the whole 

 spicule in length. Without amphidiscs of any other kind. The largest amphidiscs 

 are slender and have a thin shaft. 



The collection contains one specimen of this subgenus. 



Hyalonema tLeptonema) campanula, sp. nov. 

 Plate 81, figs. 1-26. 



A single specimen of this species was trawled in the Southern Tropical Pacific 

 at Station 4721 on 15 January, 1905; 8° 7.5' S.; 104° 10.5' W.; depth 3811 m. 

 (2084 f.) ; it grew on Ught brown Globigerina ooze. 



The terminal anchors of the macramphidiscs are slender and similar to the 

 flowers of certain species of Campanula. To this the name refers. 



Shape and size. The specimen (Plate 81, fig. 15) is somewhat fragmentary. 

 What there is of the body is an irregular mass, 18 mm. in diameter. It is drawn 

 out to a conical protuberance in one place, and from this arises a curved stalk 

 70 mm. long and about 1 mm. thick. 



The colour of the body in spirit is brown. 



The skeleton consists of pentactine and diactine pinules, pentactine, hex- 

 actine, and diactine megascleres, modified basal spicules, stalk-spicules, microhex- 

 actines, and amphidiscs. The diactine pinules are associated with ordinary 

 diactine megascleres. Protruding freely they probably formed together with 

 these spicules a fringe at the boundary between the dermal and gastral parts of 

 the surface. Some of the pentactine pinules have a very long distal ray; in 

 others, which appear to be confined to the basal part of the sponge, the distal 

 ray is of ordinary length. The acanthophores are for the most part diactine and 

 pentactine. The ampliidiscs are of three kinds, macramphidiscs, mesamphidiscs, 

 and micramphidiscs. The macramphidiscs are very abundant, the other two 

 rather rare. 



