430 PROCEEDINGS OF THE ACADEMY OF [1898. 



HYALODENDRON NA VALIUM, A NEW GENUS AND SPECIES OF 

 EUPLECTELLID SPONGE. 



BY J. PERCY MOORE. 



The type of this genus and species is one of a small collection of 

 silicious sponges gathered in Japan in 1893 by Mr. Frederick 

 Stearns, of Detroit, Michigan, and sent to the Academy of Natural 

 Sciences of Philadelphia for determination. They were collected by 

 native fishermen and brought into Yokohama harbor by the dredge 

 boats. The single specimen of Hyalodendron is the only one which 

 had been reported by the fishermen. Other than this, no data relat- 

 ing to the collection are available. The specimens are accompanied 

 by a set of sketches by a native artist. 



The species represented are, in addition to Hyalodendron, Euplec- 

 tella, anchor spicules of probably E. aspergillum Owen, Hyalonema 

 reflexa Ijima, a fine specimen of this recently described species and 

 Farrea occa (Bowerbank) Carter, an unusually large example. 



HYALODENDRON nov. gen. 



Hyalodendron navalium n. s. 



The general appearance of the type and only specimen is well 

 shown on Plate XIX, reproduced from a sketch by a Japanese artist 

 which accompanied the collection. The sponge was originally 

 about 18 inches high, but is now slightly mutilated at the summit. 

 It presents a firm base, above which rises a slender tapering "body or 

 stalk, ending in a sharp apex, and bearing numerous lateral branches 

 of various sizes, at the bases of which the sponge wall is perforated 

 by large crater-like openings. 



The base is a thin, flat and spreading, encrusting layer, which has 

 evidently conformed itself to the rocky bottom to which the sponge 

 was adherent, some fragments of which are still attached. Its 

 upper surface is uneven, but smooth and without any spines or pro- 

 cesses. It is perforated by three or four small holes. It measures 

 3ix3| inches in diameter, and is from re to £ inch thick. The 

 spicules of this region are mostly slender, more or less curved, 

 pointed diacts of various sizes, most of them being almost fibre-like. 

 They cross one another at various angles and are firmly united into 



