SCALPELLUM 241 



Scutum quadrangular with a straight occludent margin. Tergal margin hollowed out. 



Tergum triangular, rather large, with the occludent margin convex. Carinal margin 

 concave in the upper part and convex in the lower. 



Carina regularly bent with the umbo apical. Dorsal roof somewhat concave, with 

 very indistinctly indicated lateral ridges; the sides are well developed. 



Upper latus pentagonal, with the tergal and scutal margins longer than the other sides, 

 of which the carino-lateral and basal margins are the longest. Umbo situated at the apex. 



Rostrum well developed, triangular, with the umbo at the apex. The plate is not 

 covered by the rostral latera. 



Rostral latus as high as wide, with a ridge extending from the umbo to the opposite 

 corner. 



Inframedian latus of very typical shape. It consists of a primary part, which is tri- 

 angular, with the umbo at the top, and a later formed secondary or accessory upper part. 

 The umbo is thus in fully grown specimens sub-apical. The plate, seen from the side 

 (Fig. 7, k), is bowed, the two parts forming an obtuse angle. 



Carinal latus of very typical shape, pentagonal, with the umbo projecting outwards 

 beyond the carina. From the umbo two ridges can be traced; the plate is therefore 

 divided into three triangular areas. Basal margin very short. All margins straight, except 

 the lateral, which is convex. 



Capitulum swollen in the lower part. The mantle cavity in the dissected specimen was 

 filled with eggs in development. No Cypris stages were found in the specimen, but 

 there is a great possibility that the first development takes place in the mantle cavity. 



Peduncle somewhat shorter than the capitulum. The surface is covered with distinctly 

 separated transversely elongated scales. Cuticle hairy; the hairs are strong, and are 

 curved towards the base of the peduncle. 



Measurements in mm. 



Mouth-parts: Palpus conical with few bristles. Mandible with three teeth, and an 

 inner angle with a few finer teeth. Maxilla I with a small notch at the middle of the 

 front edge. Maxilla II with a continuous row of bristles on the front edge. A posterior 

 lobe with bristles is differentiated. Behind this a small maxillary lobe is formed. 



Number of segments of the cirri of the Holotype 



Cirrus I II III IV V VI C^^i^f^ 



appendage 



Segments 5 6 8 9 9 10 10 11 iiii iiii 



Cirrus I short with nearly equal rami. Cirrus II shorter than the following cirri, with 

 rami unequal in length. The segments in the longer cirri have three pairs of spines on 

 the front edge of the segments. 



3-2 



