SrOXGIIDA. 



r,s.-, 



Among Ectyonidae, Echinonema, abundant in South and South-west 

 Australia, but apparently wanting in the North and East, appears 

 here. Of the TetractineUida we have a fine new Geodine form 

 (Erylus cylindrigerus), belonging, however, to a type found already 

 in Australian and in European seas. Calcarea are relatively rather 

 abundant, at any rate in individuals, and tho new species Leucortis 

 anyuinea is of somewhat unusually large growth. 



What strikes us in a survey of the species, both of this and the 

 Melanesia!} collection, is, notwithstanding the large proportion of 

 new specific types, the comparative scarcity of forms showing marked 

 distinctive characters of generic importance which are not also 

 found in the more familiar Atlantic fauna. It is true that Carteri- 

 spongia, Phyllospongia, Ianthella, Toxochalina, Psammopemma, 

 Echinodictyum, and JRhaphidophlus have not yet been recorded from 

 elsewhere than the Indo- Pacific area, and arc probably most of 

 them peculiar to it, but several of these arc not distantly related 

 to Atlantic forms; and within this wide Indo-Pacific region (of 

 which, it must be admitted, the Eastern part is very imperfectly 

 known) the number of districts exhibiting at all peculiar shallow- 

 water sponge-faunas is small. Certainly the Western part of the 

 Indian Ocean is not one of these, and may be considered in this 

 respect, as well as geographically, as transitional between Australia, 

 South-west Asia, and the Mediterranean. 



