THORACIC CIRRIPEDES COLLECTED IN 1925-1936 231 



HoLOTYPE. Zoological department of the British Museum. 

 Distribution. East and north of Falkland Islands, 146-242 m. 



Diagnosis. Female. Capitulum with fourteen plates not much separated by chitinous 

 interspaces and covered by a hairy cuticle. Valves distinctly sculptured by longitudinal 

 ridges and growth lines. Scutum quadrangular with occludent margin slightly convex. 

 Tergum large, triangular. Carina simply arched, umbo apical, dorsal roof convex. 

 Upper latus subtriangular to pentagonal, umbo at apex. Rostrum triangular, umbo 

 apical. Rostral latus low, twice as wide as high. Inframedian latus hour-glass-shaped 

 in full-grown specimens, umbo subcentral, at the apex of a small triangular portion. 

 The rest of the valve with ribs radiating from the base. In younger specimens the umbo 

 is nearly basal. Carinal latus of a curved triangular shape, carinal margin concave, 

 basolateral margin convex, umbo at the base of the carina. Peduncle with transversely 

 elongated scales, cuticle hairy. Mandible with three teeth and an inner angle pointed 

 or with a few fine teeth. Maxilla I with a straight front edge. Maxilla II with a concave 

 front edge with bristles and a posterior lobe with bristles. A distinct maxillary lobe is 

 formed. Caudal appendage single-jointed without bristles, shorter than the proximal 

 segment of the protopodite. 



Complemental male sack-like, without cirri and valves. 



Discussion and description. This new species, which I have named after the 

 R.R.S. 'William Scoresby', Scalpelhim scoresbyi, seems to be well defined. It seems to 

 be related to S. botellmae Barnard, 1924, but diff^ers in many details as regards the valves 

 of the capitulum. The ornateness of the valves and shape of the valves of the capitulum 

 (excluding the carinal latus) suggest that some relation also exists between this new 

 species and S. brevicaulis. 



Female (Fig. 3). Capitulum covered by a hairy cuticle. There are fourteen well- 

 calcified plates not much separated by chitinous interspaces. The valves are sculptured 

 by longitudinal ridges and growth lines. 



Scutum quadrangular with the occludent margin slightly convex. 



Tergum large, triangular, with the apex acute, occludent margin straight. Tergum 

 larger than the other valves of the capitulum. 



Carina simply arched, umbo apical, dorsal roof convex, without lateral ribs. 



Upper latus subtriangular to pentagonal, with the umbo at the apex. The lower part 

 covered by the inframedian latus. The margins are straight. 



Rostrum triangular, with the umbo at the apex. 



Rostral latus low, about twice as wide as high, with the umbo at the rostral corner. 

 The lateral ridges radiating from the umbo. 



Inframedian latus hour-glass-shaped in full-grown specimens. Umbo subcentral at 

 the apex of a small triangular portion. The rest of the valve with ridges radiating from 

 the base. In younger specimens the umbo is nearly basal, but the triangular portion 

 can be traced. In very young individuals the valve is quadrangular. 



