97 



the last pair have about 15 segments, the lower being very long and representing two or 

 three segments. Two or three pairs of spines on the front of each segment and a third or fourth 

 pair much more delicate. 



Caudal appendages minute, one-jointed, cylindrical, with the extremity rounded. 

 One long and two or three much shorter hairs planted at the extremity. 



The animal as here described is a female with no trace of a penis. 



Males, two; one lodged in a pouch situated on the inner side of each scutum near 

 the occludent margin, the capitular pole slighdy projecting out of the opening of the pouch. 

 Shape oval, longest diameter 0,8 mm., shortest 0,4 mm. Structure very simple as in many other 

 deep-sea species. Surface naked, not covered with hairs or short spines. No trace of valves. 

 Prehensile antennae attached at a little distance from the peduncular pole. Muscle-fibres of the 

 sac very distinct, opening of the .sac hardly visible. 



H. M. S. "Siboga" collected this species at: 



Stat. 45. March 6, 1899. Lat. 7°24'S., Long. ii8°i5'.2E. Depth 794 m. Bottom: fine grey 

 mud. Five specimens. 



Observation. This species might also be considered as belonging to the group with 

 imperfectly calcified valves. It has some resemblance to Sc. insigne mihi from the Atlantic; it 

 can be distinguished from that species at first sight, however, i" by the shape and condition 

 of the tergum, which is V-shaped in Sc. msigtie, 2° by the presence of a rostrum, which is 

 wanting in Sc. ittsigne and 3" by the form of the carina. 



22. Scalpelhtni hiiinilc n. sp. PI. VIII, Fig. 2 and 2a. 



Valves fourteen, not covered by membrane. Scutum very large, of an irregular triangular 

 shape. Carina simply bowed with the umbo at the apex and with a flat roof bordered by ridges. 

 Rostrum extremely small. Infra-median latus with the umbo near the base, with the under part 

 very narrow and the upper part rhombiform. Carinal latus with the umbo below the middle 

 of the carinal margin, projecting beyond the line of the carina. 



This deep-sea species is represented by a large and a smaller specimen. 



The c a p i t u 1 u m is flat and rather broad, the length being slightly less than twice the 

 breadth, where it is broadest. The carinal margin is more strongly convex than the occludent 

 margin. Valves separated by narrow interspaces, that between the carina and the other valves 

 being broader. The surface of most of the valves is delicately furrowed; ridges of growth not 

 very distinct. 



The scutum is large ; its occludent marmn is straight in the under and distinctly convex 

 jn the upper part. The tergal margin is convex and slightly hollowed out near the apex which 

 is produced into a very small triangular process overlapping the tergum. The lateral and basal 

 margins slope into one another forming an arch ; at the upper extremity a short part of the 

 lateral margin forms a triangle with the extremity of the tergal margin. 



The tergum is triangular and rather elongated in consequence of the slightly convex 

 -occludent margin not being very long. A small excrescence at the carinal margin above the 

 point where the apex of the carina touches the tergum. 



97 



SIBOGA-EXPEDITIE XXXIff. 13 



