H5 



The surface of the valves seems to be delicately striated; this striation, however, is 

 made nearly quite invisible by the chitinous membrane. It is slightly more distinct on the surface 

 of the carinal latus. 



The p e du nel e is cylindrical, rather stout and short: about '/t th the length of the capi- 

 tulum. lts surface is invested with large scales, placed on five longitudinal rows, each row 

 composed of about 6 scales. The peduncle is also covered by membrane. 



Size. The length of the specimen is 14,5 mm., that of its capitulum 11,7 mm. 



It was taken by H M. S. "Siboga" at: 



Stat. 159. August 16, 1899. Lat. o°59'.i S., Long. I29°48'.8 E. Depth 411 m. Bottom : 

 coarse sand. 



Observation. This species in the shape of its capitulum and valves has a great 

 resemblance to Sc. striatum Gruvel, a species taken by the "Talisman", at a depth of 2995 m. 

 in the Atlantic not far from the Azores. But it differs from that species by its velvety membrane 

 and also by the form of the rostrum which is narrow and hardly visible in Sc. praeceps and 

 which (according to Gruvel) in Sc. striatum is: "tres net, triangulaire, allongé". 



35. Scalpcllum incertum n. sp. PI. VIII, fig. 14 and \\a. 



Valves fourteen, not covered by membrane, growth-ridges indistinct. Carina simply bowed, 

 with the umbo at the apex and with a flat roof bordered by ridges. Upper latus trapeziform 

 with the scutal margin nearly straight. Rostrum very small, hardly visible. Infra-median latus 

 triano-ular, very narrow, with the umbo at the apex. Umbo of the carinal latus very close to 

 the base of the carinal margin. 



Of this species the "Siboga" collected two specimens. 



The capitulum is flat, nearly twice as long as broad, with the apex pointed and 

 not recurved. The scutum is rather large though not very broad ; the rostral latus is much 

 narrower at the base than at its scutal margin. The carina is not strongly bowed, the lower 

 extremity reaches to near the base of the carinal latus. A chitinous interspace separates the 

 upper part of the carina from the tergum. 



The scutum is quadrangular, about twice as long as broad; the basal and tergal 

 margins are of the same length, the occludent margin is strongly convex, the lateral margin 

 very feebly convex, nearly straight. 



The tergum has a straight occludent margin, a straight scutal margin and an almost 

 straight carinal margin : the latter is slightly convex only in the lower part. 



The carina is simply and not strongly bowed. The smaller and no doubt younger 

 specimen of the two has the carina less bowed than the larger (the one figured). The umbo 

 is at the apex; the roof is not very broad but bordered by distinct ridges ; the sides are rather 

 narrow and of nearly equal breadth over the whole length of the valve. 



The upper latus is nearly trapeziform, not quite so as the angle formed by the 

 scutal and basal margins is truncated. The carinal margin is very short the scutal margin is 

 nearly straight, but slightly hollowed out. The umbo is at a little distance from the point where 

 the scutal and tergal margins meet. 



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