106 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



Biology. — Our specimens incrusted shells, corals, and nullipores; 

 they were dead. This is a shallow- water species and exclusively 

 tropical. 



Occurrence. — 



D. 5141. Jolo Light, Jolo; 6° 9' N.J 120° 58' E.; 29 fathoms 



co. S. 

 D. 5235. Nagubat Island, east coast of Mindanao; 9° 43' N. 



125° 48' 15" E.; 44 fathoms; sft. M. 

 D. 5478. Tacbuc Point, Leyte; 10° 46' 24" N.; 125° 16' 30" E. 

 57 fathoms; Sh. 

 Specimens on a Tridacna from an unknown Philippine locality. 

 Geographic distribution. — Pacific: Murray Islands, Torres Strait 

 (24-32 meters). China Sea: Macclesfield Bank (58 meters). Indian 

 Ocean : Ceylon, Borneo Bank, Makassar Straits (59 meters) ; northern 

 end of New Guinea (18 meters) ; South of the Celebes (0-36 meters) ; 

 Loyalty Islands; Singapore. 



The station of the North Pacific noted by Waters, 1898, is not 

 known to us. Jullien did not figure his specimen and said that it 

 corresponded very well to Hincks' drawing but Waters having exam- 

 ined it in 1905 at the Museum of Paris, identified it with Ellisina 

 incrustans Waters, 1898. The certain localities are those in the 

 tropical zone. 

 Plesiotypes.—C&t. Nos. 7880, 7881, U.S.N.M. 



ELLISINA PHILIPPINENSIS, new species 



Plate 8, fig. 1 



Description. — The zoarium encrusts shells and nullipores. The 

 zooecia are distinct, separated by a deep furrow, little elongated, 

 oval, ventricose; the mural rim is thick, finely granulated, much 

 enlarged at the base; the opesium is oval. The ovicell is endozooe- 

 cial, very small, transverse. The avicularium is small, transverse, 

 triangular, a little salient at the point; the mandible is short, without 

 wing, subsymmetrical, acuminate. The opercular valve is supported 

 on the mural rim (hr<=0.12 mm.). 



Measurements . — 



~ . Iho = 0.30 mm. ~ \Lz = 0.45-0.50 mm. 



Opesmmi, _ ., _ n nn Ziooeciumu _ ori n oc 



F (lo = 0.15-0.20 mm. U2 = 0.32-0.36 mm. 



Affinities. — This species differs from EUisina coronata Hincks, 

 1881, in its smaller dimensions (Lz<0.50 mm), and in its mural rim 

 enlarged at the base. It differs from EUisina incrustans Waters, 

 1898, in its more thickened mural rim enlarged at the base and in the 

 oval form of the zooecia. Our specimen did not appear in reproduc- 

 tion in February, 1908. 



