THE SPONGES. 51 



ROSSELLIDAE F. E. Schulze. 



Bathydorus F. E. Schulze. 



1S87. Balhydorus F. E. Schulze, 18S7, p. 150. 

 1S97. " F- E. Sch., Schulze, 1897, p- 14. 



1898. " F. E. Sch., Ijima, 1898, p. 46. 



Bathydorus levis F. E. Schulze. 



1895. Bathydorus laevis F. E. Schulze, 1895, p. 57, Taf. VI. Figs. 1-10. 

 1902. Bathydorus Levis " 1902, p. 78, Plate XIV. Figs. 1-10. 



Bathydorus levis spinosus, subsp. nov. 



Plate 5, Figs. 11-13; Plate 6, Figs. 1, 8. 



Diagnosis. Body calyculate. Both dermal and gastral surfaces with scattered pros- 

 talia. Autodermal stauracts densely covered with sharp spines 1-2 /i high. Distal ray 

 of autogastral hexact longer, aud with longer spines, than the other rays. Oxyhexasters 

 80-100 fi. in diameter. 



Staiion 3382, 2 specimens ; Station 3399, 1 specimen and a fragment. 



Of the specimens taken at Station 3382, one is a thin, laterally com- 

 pressed sac, Fig. 11, Plate 5, with a greatest horizontal diameter of 46 mm. 

 and a depth of 25 mm. The wall is about 1 mm. thick, thinning toward 

 the edge. The extreme lateral compression is doubtless unnatural. There 

 is a marked concavity on one side of the sac, and the base of the sponge is 

 somewhat pointed, projecting toward the concave side. The dermal sur- 

 face of the basal portion is indented by an oblique furrow about 2 mm. wide 

 and 6 mm. long, probably caused by the cylindrical body [Hijalonema root 

 spicule ?) to which the sponge was attached. 



The second specimen from Station 3382, Fig. 1, Plate 6, is much 

 broken, but fortunately the base is preserved intact. As in the other 

 individual, the sac is pointed below and concave on one side. Nearly the 

 whole of one lateral wall of the sac has been torn off. The opposite 

 lateral wall is about 60 mm. wide and 2 mm. thick, thinning toward the 

 free edge, only a part of which is natural. 



The sac in the concave region to one side of the pointed base tightly 

 grasps what is probably a Caulophaciis stalk. The stalk in question is a 

 fragment 30 mm. long and about 4 mm. thick. It is roughly cylindrical, 

 hollow, and slightly curved. Only the skeletal framework remains, which 

 consists of diacts, running for the most part longitudinally, and richly 

 connected by synapticula. 



