SCALPELLUM 



237 



Diagnosis. Female. Capitulum hairy, with fourteen well calcified plates, separated 

 by chitinous interspaces, the valves sculptured. Scutum quadrangular, apex recurved 

 and occludent margin convex. Tergum triangular, with nearly straight occludent 

 margins. Carina regularly bowed with apical umbo. Dorsal roof strongly convex. 

 Upper latus pentagonal with apical umbo. Rostrum triangular with apical umbo. 

 Rostral latus quadrangular, wide rather than high. Inframedian latus triangular with 

 apical umbo. Carinal latus quadrangular with apical umbo. Peduncle with trans- 

 versely elongated scales with chitinous interspaces. Mandible with three teeth and a 

 pectinated inner angle. Maxilla I with an indistinct notch. Maxilla II with bristles in 

 two groups. Caudal appendage single-jointed, with bristles, of the same length as the 

 proximal segment of the protopodite of cirrus VI. 



Discussion and Description. This new species, which I have named S. mognae- 

 carinoe, from the large and well-developed 

 carina, belongs, like S. liberiim, n.sp., to the 

 group of S. velutinum. From this species it is 

 well differentiated by several external and 

 internal characters. In the shape of the carinal 

 latus it is much related to S. regium, Wyv. 

 Thomson, 1873, S. moluccamim, Hoek, 1883, 

 and S.gigas, Hoek, 1883, of the Challenger 

 Expedition. These species I have studied in 

 the British Museum, and have found them in 

 other characters well separated. In the internal 

 parts this new species differs especially by the 

 single-jointed caudal appendage. In S. regium 

 the appendage is four-jointed (according to 

 Hoek) ; in S. gigas I found in the type material 

 four to six segments; in S. moluccamim the 

 appendage has five to six segments (Hoek, 

 , 1883, and Nilsson-Cantell, 1927). 



Female. Capitulum wholly covered by a thick and very hairy cuticle, and this must 

 first be removed before one can study the valves. There are fourteen plates separated by 

 chitinous interspaces, sometimes rather widely as in the larger individuals, especially 

 round the upper latus. The valves are distinctly sculptured by growth ridges and 

 longitudinal radiating lines. 



Scutum quadrangular, with recurved umbo, occludent margin slightly convex. 



Tergum triangular, with the apex acute, occludent margin like the others a little convex. 



Carina very typical, rather broad and regularly arched. Umbo apical. Dorsal roof 

 very convex, without lateral ribs, and merging into the well-developed sides. 



Upper latus pentagonal, with the umbo at the apex. The scutal margin, which is the 

 longest, hollowed out, the carinal margin convex. 



Fig. 5. Scalpellummagnae-carinae. <2. Holotype, 

 lateral view (total length 19 mm.), b. Carina. 

 c. Rostrum and rostral latera. d. Paratype 

 (St. 187), lateral view (total length 30 mm.). 

 e. Rostrum and rostral latera. 



