F. TRYBOM. TWO NEW SPECIES OF THE GENUS EUCONAXIUS. 385 



The eyes are a little more than half as long as the 

 rostrum; their visible stalk or cylindrical basal part of about 

 the same length as their rounded extremity with the cornea. 

 This latter part is either broader than, or of about the same 

 breadth as, the part first mentioned. 



The intern al antennas (Pl. 20, Hg. 3) have the two setae 

 of subequal length. The peduncle ["the basal segment of the 

 stem" of Astacus, according to Huxley 1 ], which constitutes 

 the bearer of the eyes, forming a convexity exteriorly (Pl. 

 20, fig. 3 and 4) and bearing a spine at the distal end of 

 this convexity. The distal end of the segment is itself nar- 

 rowed to nearly the same breadth as the other two joints of 

 these antennse, which joints are about equal in length and 

 are together about as long as the peduncle. On its upper 

 side the peduncle is furnished with a comparatively broad, 

 longitudinal furrow, which is covered with a row of hairs 

 springing from each side (Pl. 20 fig. 3 a). 



External antennse (Pl. 20 fig. 1 and 2) with the second seg- 

 ment ["the armiger", Strahl 2 ] produced into a long and thick 

 spine (fig. 2 a) ("stylocerite", Faxon and other authors) at the 

 base of the "scaphocerite" (fig. 2 b) [the movable acicle or squa- 

 ma 3 J, which former spine (stylocerite) attains to about one third 

 of the length of the scaphocerite. On the lower side of the 

 distal end of the third segment there is a strong but short 

 spine (fig. 2 c). The style-shaped movable scaphocerite is 

 slender and pointed, nearly as long as, and even a little 

 longer than. the fourth segment, which is a little longer 

 than the second segment with the stylocerite. The last seg- 

 ment is about one quarter as long as the fourth. The second 

 and third segments are compressed lateralty. The single fla- 

 gellum is more than twice as long as the carapace, measu- 

 red along its sides. 



The "ischiopodite" (Huxley) of the external or third max- 

 illipeds (Pl. 20, fig. 5 a) bears a very nicely serrated "crista 

 dentata" (Hg. 6), and the meropodite (b) (merus) is furnished 

 with two or three strong spines, in addition to some small 

 ones, at its lower edge. 



1 T. H. Huxley: "The Crayfish" (London 1880), p. 172. 



2 Strahl: p. 1061, fig. 4. 



3 Confer W. Faxon: ''The Stalk-eyed Crustacea". Mem. of the Mus 

 of Comp. Zoologv at Harward College. Vol. XVIII. XV (Cambridge U. S. 

 A. 1895) p. 103. 



