528 TAGE SKOGSREnr, 



shell there is a moderate number of rather short bristles, arranged in a single distinct row. 

 Posteriorly, somewhat in front of the spine-bearing list, this row becomes very dense and at the 

 same time the bristles become longer and coarser; it continues up along the ventral quarter or 

 third of the spine-bearing list, running about half way between the latter and the margin of 

 the shell (fig. 5). The spine-bearing list has rather few hyaline spines, about 19 — 20, of somewhat 

 varying size, and has a sparse row of short bristles, about one or two between each hyaline 

 spine. The double line drawn in fig. 5 inside the posterior margin of the shell corresponds to 

 a sharp ridge; the part of the shell between this ridge and the posterior margin of the shell is 

 situated rather considerably laterally — i. e., when the shell is looked at from inside, it is consid- 

 erably deeper — of the part between the ridge and the spine-bearing list; a ridge of this sort 

 is characteristic for both the valves. Just inside the dorsal half of this ridge there is a sparse 

 row of broad pores (six such pores were always observed on the specimens investigated); in the 

 specimens investigated these pores did not seem to be furnished with low hyaline pegs. In 

 addition a rather dense and irregular row of fine pores issues near this ridge. 



First antenna (figs. 6 and 7): — This is very like the corresponding limb in 

 A. Grimaldi. We may note: It is seven-jointed, the third and fourth joints are not united to 

 each other. Of the six anterior bristles on the third joint no. .5 has short hairs. The a-claw 

 on the end joint is only slightly longer than the anterior side of the fifth and sixth joints; it has 

 only extremely weak pectination dorso-proximally. The f-bristle has five, the c- and g-bristles 

 six or seven sensorial filaments. The first and second joints are rather abundantly furnished with 

 hairs; the second joint, however, as in A. Grimaldi, has no row of hairs along the distal boundary. 



Second antenna (fig. 9) : — Very like that of A. Grimaldi. The protopodite 

 has a short bristle disto-medially close to the exopodite. E n d o p o d i t e: On one specimen 

 this was abnormally developed on one side, reminding one very much of this branch in the 

 male in the penultimate larval stage; the second joint had a very small bristle near its distal 

 boundary; the bristle of the end joint was displaced somewhat proximally (fig. 10). 



Mandible (fig. 11): — Protopodite: Coxale: The scythe-shaped process 

 (fig. 12): The part situated distally of the main spine grows narrow rather rapidly, but 

 not so rapidly as in A. Grimaldi, into a fine point; its ventral edge is slightly concave 

 distally and slightly convex or almost straight proximally; it forms, just near the main 

 spine, a rather weak spine which points proximally. The distance between the point of the 

 process and the main spine is rather slightly shorter than the distance from the latter to the 

 jjroximal ventral spine. The dorsal bristle is fixed somewhat nearer the main spine than its 

 distance from the point of the process, and somewhat, though only rather slightly, distally of 

 the main spine ; it extends rather slightly beyond the point of the process. The dorsal serrate 

 teeth are rather few in number, but comparatively large. The main spine is rather strong. There 

 are four ventral spines, the two distal ones of which are rather weak, the two proximal ones 

 rather strong. Between the distal ventral spine and the main spine the ventral edge is finely 

 serrated; the serrate teeth point proximally; this serration may sometimes be more or less 

 completely missing — presumably on account of wear. On the part distally of the main spine 

 there are only a few — two or three were observed — transverse rows of hairs. The rod-shaped 



