l89>- N*0. 8. SOUTH-AFRICAN EXTOMOSTRACA. i; 



acute angle with the ventral edge, and carries, anteriorly, a few small den- 

 ticles. The ventral edge of the head is quite straight and obliquely 

 ascending, terminating with a very small rostral projection just in front 

 of the insertion of the antennulae see also fig. 3 . Viewed from abo\'e 

 or beneath (fig. 2], the head appears rather broad, nearly semicircular in 

 outline, on account of the greatly prominent fornix, which latter joins the 

 carapace on each side at a very acute angle. 



The surface of the shell, as in other species, is sculptured with clo- 

 selv set, oblique striae, partly anastomosing with each other. These striae 

 are especially distinct on tlie vahular part of the carapace, running pa- 

 rallel to the hind edges, and. anteriorly, forming a somewhat irregular net- 

 work. 



The eye, located just within the piojecting frontal part of the head 

 see fig. 3, is rather large, with distinct crystalline bodies, and dark brown 

 pigment. 



The ocellus (ibid.), on the other hand, is very small, subrhomboidal 

 in fonn, and occurs just in Iront of the insertion of the antennulæ. 



The latter appendages ^ibid.) exhibit the usual subfusiform shape, and 

 carry each, in addition to the apical bundle of olfactory papillæ, a delicate, 

 anteriorly pointing sensory bristle, arising from a knob-like prominence 

 about the middle of the anterior edge. The\- are, as in other species, 

 movably articulated to the shell of the head, and are. generally, extended 

 obliquely beliind, without, howe\er. in this species being co^'ered by the 

 anterior part of the calves. 



The antennae (see figs, i & 2] exliibit the structure characteristic of 

 the genus. 



The tail (see fig. i) also, does not differ essentially in its general 

 form from that in other species. As in these, it is rather broad and com- 

 pressed, exhibiting, dorsally, 2 ilistant falciform processes for occluding the 

 matrix behind. Its terminal part (fig. 4), has the posterior edge slightly 

 bulging in the middle, and terminates in an obtuse point carrying the 

 caudal claws. The anal sinus is well marked, and defined, ab;jve, by an 

 obtuse prominence : it is armed, on each side, with about ro denticles, the 

 outer of which rapidly increase in size, and are strongly curved. The 

 terminal claws (fig. 5) are very slender, and but very slightly cuned; 

 they want all traces of secondary spinules, but are finely ciliated along 

 their concave edge. 



The alimentary tube (see fig. i), is rather wide, and forms, anteriorly, 

 only a very slight curve. The cœcal appendages are short and 

 deflexed. 



Vid-Selsk. Skritter. iL-X.JQ. 1S95. No. 8. 2 



