8/ 



carinal margin describes a curve, that part which represents the basal margin of the same valve 

 in other species being verj- short. 



The rostrum (fig. 14a) is small, triangular, with the base directed towards the peduncle. 

 Its ape.x separates the two umbones of the rostral latera from one another; though small the 

 rostrum is distinctly visible at the surface. 



The rostral latus is e.xtremely low, its scutal and basal margins running nearly 

 parallel to each other. 



The infra-median latus is also small. It has a triangular .shape with the umbo 

 at the apex. 



The carinal latus has a convex carinal and a hollowed out upper margin; where 

 they meet the umbo is seated; that part projects outwards and forwards. 



The peduncle is robust, cylindrical and rather long, being about 7/ds ^s lona as the 

 capitulum. It is covered by prominent scales placed in five longitudinal rows. 



Size. The length of the animal is 30 mm., that of the capitulum 19 mm. 



The specimen representing this species was collected by the "Siboga" at: 



Stat. 256. December u, 1899. Lat. s°26'.6S., Long. I32°32'.5E. Depth 397 m. Bottom: 

 greyish green mud. 



Observation. This species is no doubt nearly related to the Atlantic species Sc. 

 velutinum Hoek. Yet it can be easily distinguished from that species b)- the form of the 

 upper latus, by the rostrum and by the shape of the carinal latus. It beloncrs to 

 the same group of species as Sc. diota n. sp. but the rostrum and the infra-median 

 latus of the latter species are so different that there can be no question, I think, of these 

 two forms being distinct. 



16. ScalpelluDi diota n. sp. PI. VII, fig. 15 and 15^'. 



Valves 14, covered with hairy membrane. Carina simply bowed, large. Valves of the 

 lower whorl small, increasing in height from the rostral to the carinal side of the capitulum. 

 Carinal latus with the umbo at the strongly recurved apex. 



This species is represented by one specimen only. 



Capitulum with the occludent margin nearly straight and the carinal margin very 

 strongly convex, with the upper valves large and those of the lower whorl small. The colour 

 of the specimen (in spirits) is light pink, large red spots being observed along the margins of 

 the larger valves etc. 



Scutum quadrilateral, not quite twice as long as broad. Occludent margin nearly 

 straight, lateral margin convex, apex produced, pointed, slightly overlapping the tero-um. 



Tergum large, triangular. Occludent margin nearly straight; apex pointed, slightly 

 produced, hardly curved towards the carina. 



Carina simply bowed, roof flat, a depression being only visible at the base between 

 the two carinal latera. The roof increases in width very considerably from the apex to the 

 base. Sides flat, rather narrow. 



87 



