1 in 



The rostrum is hardly visible, being covered on both sides by the margins of the 

 jtral margins of the two rostral latera do nol touch, io thal a narrow 

 strip of the small rostrum remains uncovered. 



The rostral latus is quadrangular with the angle formed by the lateral and scutal 

 ins truncated. lts basal margin is much shorter than the scutal margin. 



rhe infra-median latus is triangular, very narrow, with the umbo al the api 

 The api ■ not quite reach to the truncated angle of the upper latus. 



The carinal lams is quadrangular, with the carinal margin onlj ver) ilightly Ik. Huw..! 

 <nu, with the upper margin straight .uu\ the basal margin slightly shorter than the lateral margin. 

 I umbo is very close tq the lower extremity of the carinal margin and does not pn 

 beyond the lin<- of the carina. 



The peduncle is short, cylindrical but laterally compressed. The scales on the surfa 

 are- narrow, horizontally extended and ai some distance from one another. The) are arranged 

 in seven longitudinal rows: three on each side and one on the carinal of the pedui 



Then about 8 scales in each longitudinal row in the largest specimen. 



Size. The total length of the largest specimen was u mm., that of its capitulum 8 mm. 



Both specimens were found attached to a brownish-coloured thread or fibre the nature 

 of which is unknown to me. 



They w< llected by II.M.S. "Siboga" at: 



St.it. t6i. August ij, 1899. Lat. i° io'-S S., Long. 130 9 I - Depth 798 m. Bottom: muddy 

 sand. 2 specimens. 



Observation. This species has a great resemblance to various other species, for 

 example, to Sc. gracile n. sp. It differs from ii by the shape of the upper latus and of the 

 carinal latus. as also by the presence of a rudimentary rostrum of which no tracé could be found 

 in Sc. gracile. But tor the shape of the carinal latus it would be considered as belonging to 

 the same group of species ■ > - Sc. formosum, Sc. truncatum (which have a rostrum) and .is 

 Sc. tenue. Se. proclive and Sc. deforme (species without a rostrum). 



36. Scalpellum fissum n. sp. PI. IX, fig. 1 and 2. 



Valves thirteen. Tergum with the apex recurved. Carina simply and not strongly bowed 

 with the umbo at the apex, with narrow sides and with a laterally convex roof, bordered by 

 ridges. Upper latus with a longitudinal fissure. Infra-median latus wine-glass shaped. Carinal 

 latus with the umbo at the base. 



The curious species is represented by four specimens, two large and two smaller ones. 



The capitulum is rather flat and covered by a delicate membrane to which Radiola- 

 rians etc. adhere. Margins of the valves distinct. The qccludent margin convex, in the smaller 

 specimens even more strongly bowed than the carina! margin. Apex of the tergum recurved. 

 Valves of the lower whorl well-developed. 



The se 11 turn is quadrilateral with the occludent margin convex. The tergal margin is 

 vex in the larger specimens; in the smaller it is nearly straight. The lateral margin is 



n6 



