Lat. 5° 44.7' S., long. 82° 39.5' W. 



NYCTIPHANES SIMPLEX. 227 



11. Nyctiphanes simplex II. J. H.w.sen. 

 Plate 6, figs. 2a-2i (adult and subadult); Plate 7, fig.s. la-lb (Young). 



1911. Ni/rtiphanes simplex H. J. Hansen, Bull. Mus. Ocean. Monaco, no. 210, p. 20. 



Lat. 29° 52' N., long. 116° 56' W. Surface. 3 specimens. 

 Lat. 2° 13.3' S., long. 89° 42.2' W. Surface. 1 ovigerou.s female and 1 young. 



Surface. 7 immature or young speci- 



specimens. 

 100 fms. to surface. 2 inmiature or 

 young specimens. 

 Lat. 5° 57.5' S., long. 80° 50' W. Surface. 43 specimens (18 young). 

 Lat. 2° 40.4' S., long. 90° 19.3' VV. 300 fms. to surface. 2 adult specimens 



Dcscripfiori. — The frontal plate moderately long, triangular, subacute, 

 with its margin considerably raised; and the median keel begins a little behind 

 the tip (fig. 2a) and reaches the distinct cervical groove; the median area be- 

 tween the frontal plate and that groove is considerably vaulted. As in the other 

 forms of the genus, the carapace of the adult and subadult has no denticle or 

 angle on the lateral margin. 



Eyes moderately large. — The antennular peduncles very characteristic; in 

 both sexes the first joint is, at the outer distal corner, produced in a very conspicu- 

 ous protuberance which, seen from above (figs. 2c and 2e) is directed forwards and 

 somewhat outwards, is subconical, very thick at the base and acuminate at the 

 end; the upper terminal leaflet is very large, directed somewhat or much back- 

 wards and considerably or a little upwards; considerably longer than broad 

 at the base; scarcely twice as broad at the base as at the end, which is broadly 

 rounded or nearly truncate with the terminal outer angle produced into a small 

 triangle and frecjuently curved considerably upwards and forwards (fig. 2d); 

 the upper surface of the leaflet is excavated, especially near the base; finally, 

 outwards below the base of the leaflet a transverse, vaulted part is seen. The 

 second joint in the female (figs. 2d and 2e) is very long, somewhat slender, with 

 an oblique, subacute tooth at the upper distal inner angle; in the male (fig. 2b 

 and 2c) this joint is a little shorter and conspicuously, even considerably thicker 

 than in the female, and the upper distal tooth is much broader, subvertical, 

 triangular, or somewhat bifid. Third joint in both sexes much shorter than 

 second, in the female slender, somewhat keeled above towards the end and the 

 keel terminating in a short, acute tooth (fig. 2d); in the male (figs. 2b and 2c) 

 this joint is much thicker, without any tooth, but, seen from above, conspicu- 

 ously curved, with the outer margin very convex, the inner somewhat conca\'e 

 and near its middle adorned with a Ijiuulle of three short and verv strong setae. 



