CRYPTOMYSIS. 203 



CRYPTOMYSIS, gen. nov. 



Description (based on the female). — Body somewhat slender. — Carapace 

 produced into a moderately large, triangular frontal plate (Plate 3, fig. 2a) and 

 posteriorly not covering the entire cephalothorax. 



Eyes very large, with short stalks. Antennal squama (fig. 2b) somewhat 

 elongate, lanceolate, narrow, with a transverse suture and setose along both 

 margins. — Labrum obtuse in front, without process. — Left mandible (figs. 

 2c-2e) has the incisive part well developed, a moderately strong, movable lobe, 

 a couple of thick, digitate setae and the molar process somewhat long and thick; 

 the palp is proportionately slender, its second joint (fig. 2e) somewhat curved, 

 with its inner margin adorned with a row of regularly arranged, spiniform 

 processes, each of which has a seta at the middle of its front margin; third 

 joint of the palp rather short. — Maxillulae (fig. 2f) with the outer joint somewhat 

 slender and a little angular at the middle of its exterior margin. — Maxillae 

 (fig. 2g) somewhat elongate and narrow, with the exopod small and very narrow 

 and the terminal joint not expanded distally and more than twice as long as 

 broad. — Maxillipeds (fig. 2h) with first and second joints very long and moder- 

 ately slender, first joint terminating in a free, minute lobe and second joint 

 with a small lobe; third, fourth, and fifth joints each not longer than broad 

 and without appreciable lobes; terminal joint small, triangular; claw well 

 developed. 



Gnathopods (fig. 2i) with second joint long and thick, without any real 

 lobe; third and fourth joints somewhat small, transverse; fifth and sixth joints 

 rather long, very slender and the fifth nearly naked; the claw somewhat long 

 and strong. — The thoracic legs wanting excepting some exopods and a single 

 endopod; the latter (fig. 2k) is slender, with fourth joint a little shorter than 

 the fifth and a little longer than the sixth, which is divided by a transverse articu- 

 lation near its end ; only a few rather long setae on the endopod. 



Uropods (fig. 21) slender, with both rami setose along both margins as in 

 the subfamily Mysinae; the otocyst well developed. — Telson (figs. 21 and 2m) 

 quite aberrant; it is somewhat short, tapering considerably from the broad 

 base to a little beyond the proximal two thirds of its length and then widening 

 again, the terminal part being much broader than long, with the terminal margin 

 nearly straight at the middle and broadly rounded at the sides; the whole 

 margin of the terminal transverse part of the telson and the distal part of the 

 lateral margins in front of that terminal part furnished with thick spines. 



