6 G. o. SARS. M.-N. Kl. 



The head does not exhibit any pronounced dorsal crest, and is only 

 defined from the carapace above by a very shallow sinus. Seen laterally 

 (fig. 2), it exhibits a somewhat unusual form, its dorsal part being, as it 

 were, gibbously produced, with the upper edge strongly cur'\'ed in front. 

 The anterior edge declines obHquely towards the front, and is sometimes 

 slightly sinuated below. It joins the inferior, perfectly straight margin by 

 an abrupt, almost angular bend. The rostral projection is very short and 

 continuous with the lower edge, its tip being blunted. The fornix is 

 strongly prominent, and terminates on each side in a rectangular, project- 

 ing corner. When the animal is viewed dorsally or ventrally (fig. i), the 

 edges of the fornLx form, together with the anterior extremity of the head, 

 a perfectly even curve, giving the head, in that Aàew, an almost semi- 

 circular outline. 



The e\^e (see figs, i, 2, 10) is well developed, and located just within 

 the angular bend of the front. It exhibits a number of very distinct crys- 

 talline bodies projecting from the dark ocular pigment. 



The ocellus is extremely minute, but distinct, and occurs at some 

 distance behind the eye, being imbedded within a projection of the cere- 

 bral ganglion. 



The antennulae (see fig. 3) are quite immobile and very small, though 

 distinctly projecting from the shell of the head, just behind the rostral 

 prominence. They are tipped with the usual delicate olfactory papillae, 

 and have besides each a single very minute sensory bristle. 



The antennae (see fig. 2) exhibit the usual structure, and are rather 

 powerful, with both the scape and the rami finely hair}^ 



The tail has the dorsal processes (see fig. 2) verj^- large and lappet- 

 shaped, the 2 upper ones being, as usual, the largest, and arranged in 

 close approximation at the base, though somewhat diverging at their 

 extremities. The 2 lower ones are quite confinent, forming together a 

 broad lamellar expansion, finely hair}^ at the edges. The terminal division 

 of the tail (fig. 4) is conically tapering, with the dorsal margin nearly 

 straight. The anal denticles occupy • the distal half of this division, 

 and are, as usual, arranged in a double row, flanking the anal fissure. 

 They are of nearly uniform size and strongl}^ recurved, their number 

 being from 18 to 20 on each side. Above the anal denticles the dorsal 

 face of this part is clothed with small appressed spikes. The terminal 

 claws (see fig. 5) are comparatively short and stout, and are each armed 

 at the base with a dense row of slender spinules, about 8 in number, 

 their outer part being finely ciliated along the concave edges. The caudal 

 setae are well developed, biarticulate, and densely plumous. 



