294 HYALONEMA (PRIONEMA) FIMBRIATUM. 



slender distal rays as the gastrals of H. hercules. It is also to be noted that 

 H. (P.) pinulifusum possesses amphidiscs with serrated teeth, while Schulze 

 does not mention the occurrence of such amphidiscs in H. hercules. From 

 H. (P.) agujanum, which agrees with H. (P.) pinulifusum quite well in regard to 

 the amphidiscs, and indeed from all other Amphidiscophora with the exception 

 of the above mentioned H. hercules, it differs by possessing large pinules with 

 thick spindle-shaped distal ray. It is also to be noted that H. (P.) agujanum 

 differs from it in its general appearance. 



Hyalonema (Prionema) fimbriatum, sp. nov. 

 Plate 59, figs. 1-6; Plate 60, figs. 1-34; Plate 61, figs. 1-11; Plate 62, figs. 1-45; Plate 63, figs. 1-28. 



Four fairly complete and three fragmentary specimens of this species were 

 trawled in the Central Pacific : the four well-preserved ones and one of the frag- 

 mentary ones at Station 4742 on 15 February, 1905; 0° 3.4' N., 117° 15.8' W.; 

 depth 4243 m. (2320 f.); they grew on very light, fine Globigerina ooze; the 

 bottom-temperature was 34.3°; the two other fragmentary ones at Station 4740 

 on 11 February, 1905; 9° 2.1' S., 123° 20.1' W.; depth 4229 m. (2422 f.); they 

 grew on dark gray Globigerina ooze; the bottom-temperature was 34.2°. 



The anchor-teeth of certain very numerous amphidiscs bear broad, fim- 

 briate, marginal frills. To this the name refers. 



Shape and size. The well-preserved specimens from Station 4742 are 

 flattened disc- or lens-shaped and regular, broad-oval to circular (Plate 62, 

 fig. 30) or slightly irregular, wavy in outline (Plate 62, fig. 29). The largest 

 regular specimen appears as a biconvex lenticular disc. It is 31 mm. long, 

 28 mm. broad, and 10 mm. thick in the middle. Towards the margin it thins 

 out to about 3 mm. One of the faces of the disc bears a rather eccentrically 

 situated rounded protuberance 3 mm. in height, from which, in life, the stalk 

 arose. Where the superficial membranes are intact the surface is continuous 

 and destitute of larger apertures. In other places it is porous. Two of the 

 three other well-preserved specimens from Station 4742 are similar. In one 

 (Plate 62, fig. 30) the disc measures 25 by 23 by 12 mm., and has one convex, 

 broad and low conic face and one flat face. The protuberance from which 

 the stalk arose is situated on the flat face; this is the dermal. The third regular 

 specimen is 20 mm. in maximum diameter. The slightly irregular specimen 

 (Plate 62, fig. 29) is a lamella 35 mm. long, 27 mm. broad, and 6 mm. thick in 

 the centre. It thins out distally, the somewhat wavy margin being 1-3 mm. 



