SYSTEMATIC REPORT 81 



very slender and curving inward somewhat distally; armed with a single small spine on the ventral 

 surface near the margin distal to the statocyst (Fig. 13 J). Telson slightly longer than the sixth abdo- 

 minal somite; lateral margins almost straight and converging distally; armed along the distal five- 

 ninths of their length with 10-13 l° n g slender spines of almost equal size ; apical lobes each armed with 

 a single very long slender spine which is nearly one-eighth of the length of the telson. There is no 

 trace of the two spines which in other species of Boreomysis flank the terminal apical spine on its 

 inner side. Cleft less than one-sixth of the length of the telson ; no proximal dilatation ; margins convex 

 distally; armed with n-i2longslenderteeth which are progressively shorter towards the base(Fig. 13 J). 

 Length, largest adult male, 9 mm. ; females with fully developed brood sacs, 8-4 mm. 



Fig. 13. Boreomysis insolita sp.n. A, adult female in dorsal view, x 10; B, anterior end of adult female in lateral view, x 10; 

 C, profile of anterior end of carapace and eye, x 10; D, right antennular peduncle of adult female, x 30; E, right antenna of 

 adult female, x 30; F, endopod of second thoracic appendage, x 30; G, second pleopod of male, x 30; H, third pleopod of 

 male, x 30; J, telson and left uropod in dorsal view (adult female), x 30. 



Remarks. This species can readily be recognized by its small size and delicate slender form and by 

 the rounded uptilted anterior margin of the carapace showing no trace of a rostral angle. The form 

 of the antennal peduncle is quite distinctive and I know of no other species in the genus which has 

 a similar form. The unusually long spine at the distal end of the outer margin of the scale and the 

 long terminal spine arming the apical lobes of the telson together with the few spines arming the lateral 

 margins of the telson make the species readily recognizable. Few and relatively long spines on the 

 margins of the telson are frequently a sign of immaturity, but in the present material there are several 

 definitely adult specimens of both sexes. 



Distribution. The specimens were taken in depths of 250-100 m., 100-50 m. and 50-0 m. at 

 two stations in the Benguela Current to the west and the south-west of Walvis Bay, South Africa. 



