6; 



which are figured by. Darwin as freely projecting beyond the rostral and carinal margins of the 

 capitulum, are much less strongly developed and hardly projecting in the specimens from Jedan. 

 So far as I know this is the first time, that specimens of this species have been collected 

 since the publication of Darwin's Monograph. He knevv the species from specimens found in 

 the Swan River, Australia, attached to a coralline, and from Port Western, Bass Straits 

 (Astrolabe Voyage) : the Swan River is on the west side of Australia, Bass Straits on the south. 

 The Jedan Islands, the third place where the species occurs, lie between the north of New 

 Holland and New Guinea. [Gruvel \ found three specimens of Sc. Pcroni in the collections 

 of the Paris Muséum d'histoire naturelle; but their habitat is unknown. He pointed out that 

 these specimens are not covered by a complete coating of fine and numerous hairs as in 

 Darwin's description and figure]. 



6. Scalpelhim iincus n. sp. PI. V, fig. 15; PI. VII, fig. 2, 3. 



Valves thirteen. Carina ancjularly bent with the umbo in the middle of its leneth. 

 Rostrum rather large. Three pairs of latera. Upper latus pentagonal. Sub-carina pyramidal, 

 standing out bevond the surface of the carina. 



Of this species there are three specimens representing two different forms. 



The capitulum is fiat, broad in the middle, the upper part slightly produced. It has 

 1 3 valves with narrow, but distinct intervals. The valves are not covered with membrane in 

 the one (Station 285) and are covered by a resistant and pigmented membrane in the two 

 other specimens (Station 47 b ). 



Scutum middle-sized, with the upper end pointed; nearly quite flat; lateral margin 

 near.ly straight, parallel with the occludent margin. In the specimen without membrane a distinct 

 swelling is visible at the place where, on the inner side, a pit is present for the adductor muscle. 

 Basal margin composed of a longer and a shorter segment, making an angle with one another. 



Ter gum large, triangular, flat. Occludent margin distinctly convex towards the apex 

 which is recurved ; carinal margin projecting a little above the apex of the carina ; scutal margin 

 slightly convex. 



Carina bowed, laterally strongly compressed, and thus internally deeply concave ; upper 

 portion above the umbo nearly as long as the part beneath the umbo ; roof laterally convex 

 growing wider from the umbo downwards and indistinctly separated from the parietal parts 

 of the valve. 



Upper latus pentagonal, with the apex rounded and the umbo at a short distance 

 from the apex. 



Rostrum of considerable size, internally concave; outline of the upper portion triangular, 

 of the lower portion trapeziform. The umbo is at the apex, which, especially in the specimens 

 covered with membrane, slightly projects beyond the occludent margin of the capitulum. 



Rostral latus very thick and solid, large, irregularly pentagonal, with the umbo near 

 the rostral margin and near the base of the valve and distinctly projecting outwards. 



1 GrüVEL, A., Révision de» Cinhipèdes. Nouveil. Archiv. d. Muséum. (IV). IV, 1903, p. 234. 



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