32 



R. KIRKPATRICK. 



The auisocheles of the embryos nearly resemble the smaller kind of these spicules 

 found in the choanosome of the type specimen. 



The type specimen (No. 184) was dredged near Winter Quarters, No. 11 hole, 

 28 fms. ; specimens 202, 287, and 289 were dredged from No. 10 hole, 130 fms. 



DIFFERENTIAL DIAGNOSIS OF THE FOUR SPECIES OF IOPHON WITH MODIFIED ACANTHOSTYLES. 



TEDANIA VARIOLOSA. 



(Plate XXL, figs. 1, la, and Plate XXV., fig. la-b.) 

 1907. Tedania variolosa Kirkpatrick (10a. p. 279). 



Sponge in form of a mass of thick rlabellate or digitate fronds arising from a 

 common base ; with circular sphiuctrate oscules, each about 1 cm. in diameter, situated 

 at the summits, or along the upper edges of the branches, the canals into which they 

 lead extending nearly to the base of the branches. General surface of the sponge 

 covered with circular pore areas each about 4 mm. in diameter, the oval or circular pores 

 being about 90 n in diameter, and the strands of the poral reticulum about 30 /j. in 

 breadth. Colour in spirit, pale brown. Consistence, soft and fleshy, being easily torn. 

 Flagellated chambers, 42 x 35 M, oval, aphodal, with aphodus (in a measured 

 example), 13 M long- 

 Skeleton. Choanosomal skeleton formed of loosely agglomerated compound, 

 longitudinal or main bundles about 1 mm. in diameter, curving out to the surface as 



