20 



the post-cervical groove, so that it appears not at all compressed laterally. The rostrum 

 incliided, the carapace appears a little longer than one-third the length of the abdomen ; both 

 the carapace and the abdomen are smooth and polished. The single tooth of the rostrum is 

 situated just behind the orbital margin of the carapace, the rostrum reaches almost to the 

 middle of i*' antennular article and a little beyond the micldle of the eye-peduncle ; it is 

 directed forward with the pointed tip slightly turned upward. The distance between the dorsal 

 tooth and the tip of the rostrum measures about one-fifth the distance between the tip and 

 the posterior margin of the carapace. The ascending lower margin and the upper margin 

 between the dorsal tooth and the tip are fringed with long, ciliated hairs. Carapace dorsally 

 carinate throughout its length. Both the cervical and the post-cervical groove are deep and 

 very closely approximate dorsally, the distance between the two grooves is just one-fifth the 

 distance from the post-cervical groove to the posterior margin of the carapace. (In younger 

 specimens the two grooves are comparatively less approximate dorsally, the proportion between 

 the two distances being 4^. in the male which is 22 mm. long). As regards the arrangement 

 of the grooves and carinae on the sides of the carapace, this species resembles Genn. borealis 

 (Rathbun, Decapod Crustaceans North West coast of Xorth America, 1904, p. 147, Fig. 88); 

 the gastro-frontal groove is, however, directed towards the rostral tooth and the post-cervical 

 groove does not meet with the gastro-hepatic sulcus. Antennary and infra-antennary angles 

 acute, branchiostegal spine small. The transverse cardiaco-branchial ridge is rather obtuse, 

 does not reach the posterior margin of the carapace and fades away before reaching the post- 

 cervical groove. 



The 6''^ abdominal somite alone is carinate, the carina is obtuse and does neither reach 

 the anterior nor the posterior extremity of the upper margin; this somite, 5,5 mm. long and 

 just twice as long as wide, is almost twice as long as the 5''' (3 mm.). The telson, 3,7 mm. 

 long, little more than half the length of the 6"^ somite, reaches just to the middle of the 

 endopod of the caudal fan, but not yet to the middle of the exopod; the telson tapers rather 

 strongly, is slightly grooved and bears two movable spines at the extremity. 



Eye-peduncles flattened above, with the large, acute, conical tubercle somewhat turned 

 upward; the globular, dark red brown coloured cornea is a little broader than the peduncle and 

 its diameter is just one-ninth the length of the carapace, rostrum included ; there is a small speek 

 of black pigment near the cornea. The small spine on the outer margin of the 1*' antennular 

 article does not yet attain the end of the cornea; the 3'^ article, measured dorsally, appears one- 

 third to one-half longer than the 2"'^ and both are together as long as the i^'; the thickened basal 

 portion of the upper flagellum is almost as long as the 2"<i and the 3"' articles taken together. 



The antennal scale, 5,75 mm. long, measures nearly two-thirds the length of the carapace 

 and reaches almost with the length of 3'''^ article beyond the antennular peduncle ; the scale, 

 somewhat more than 3-times as long as the greate.st width (1,7 mm.) near the base, narrows 

 rather strongly, the width of the obtuse tip measuring but Yg or Y9 the greatest width. The 

 inner margin of the scale is straight and the terminal spine extends beyond the tip of the 

 blade as far as the latter is wide. 



Mandibular palp about as in Genn. Bouvieri. Merus of 2"'! maxilliped less than twice 



