46 "ENDEAVOUR" SCIENTIFIC RESULTS. 



Diagnosis. Antennae subequal, short, with reduced 

 flagella ; upper antennae with accessory flagellum. First 

 gnathopod large, simple; second gnathopod of usual type 

 in the Lysianassidae. First peraeopod developed into a sub- 

 ch elate grasping organ with greatly broadened propod. 

 Telson entire with extremity rounded. In general shape, 

 side plates, remaining peraeopoda and uropoda resembling 

 the usual type of the family. 



Length, about 6 mm. 

 Colour (in spirit), whitish. 



The development of the first peraeopod in this species is 

 most extraordinary, and I know nothing at all like it in 

 the other Lysianassidae. At first I suspected that it might 

 be a male character, but it is present in all the numerous 

 specimens that I have been able to examine, although there 

 is none among them that I am perfectly certain is a female. 



The first gnathopod is also somewhat peculiar, being 

 large in proportion to the second and somewhat ungainly 

 in form, the distal portion lying in a different plane from 

 the basal joints and being so curved that it is difficult to 

 get a satisfactory view of the appendage. The very reduced 

 flagclla of both antennae are noteworthy, but in the remain- 

 ing characters the animal presents the usual type found in 

 the family Lysianassidae. The following is a detailed 

 description : 



Both antennae (Fig. 4 ft) are short and stout, the flagella 

 being greatly reduced. In the upper antenna the first joint 

 is much larger than the second, and the third joint is indis- 

 tinguishable, being apparently sunk in the hollow end of 

 the second. The primary fiagellum is about one-half the 

 length of the second joint of peduncle, composed of about 

 five very short joints. The accessory flagellum is about half 

 the size of the primary. The second antenna is of about 

 the same length as the first, the antepenultimate joint 

 slightly longer and considerably broader than the penulti- 

 mate. The flagellum is very short, apparently composed of 

 two or three small joints. 



The eyes are large, oval. 



In the mandibles (Fig. 4 c) the palp is well developed 

 and arises at some distance from the base, it is considerably 

 longer than the mandible itself, its second joint the longest* 



