52 THE VOYAGE OF H.M.S. CHALLENGER. 



The present species is a true Munnopsis by reason of the broad anterior region of the 

 thorax and the narrow posterior region; it agrees closely with Munnopsis latifrons, 

 Munnopsis typica, &c. 



The single specimen is a male and measures 12 mm. in length. 



The head is small and is deeply sunk into the first thoracic segment, the region 

 between the antennae and antennules of either side is wide, as in Munnopsis typica, 

 though perhaps not so wide as in Munnopsis latifrons. 



The first segment of the thorax is very narrow ; the second is quite the largest of the 

 four segments ; on a lateral view (see PI. XIV. fig. 9) this segment is seen not only to 

 have a considerably greater antero-posterior diameter than the preceding or the succeed- 

 ing ones, but also a greater vertical extension ; its dorsal surface is strongly arched, and 

 is raised some way above the general body surface. 



The third and fourth segments are subequal and each rather smaller than the second ; 

 the transverse diameter of the third segment is about ecpial to that of the second, 

 and here the body of the Crustacean is widest ; the fourth segment of the thorax 

 is distinctly narrower ; the hinder margin of the third and fourth segments are concave, 

 that of the fourth particularly so. 



The rest of the thorax is very much narrower than the anterior region ; of the 

 three segments of which it is composed, the first is considerably the longest ; the second 

 and third are short and subequal. 



The abdominal shield is long and narrow, and terminates posteriorly in two short 

 projections on either aide of the median line, to the outside of which the uropoda are 

 attached. 



Along the median line of the abdominal shield is a raised convex area, which narrows 

 gradually towards the posterior extremity ; on either side of this is the lateral convex 

 area. 



This species comes nearer to Munnopsis typica than either of the following ; an 

 obvious distinction between the two species is the absence in Munnopsis gracilis 

 of any spiny processes such as are found on certain of the segments of Munnopsis 

 typica ; furthermore, the fifth segment of the thorax is distinctly longer than either of 

 the two succeeding ones, though not so markedly so as in Munnopsis australis. In 

 Munnopsis typica these segments are more equal in length. 



The illustrations of this species are from drawings by the late Dr. v. Willcmoes-Suhm. 



Station 168, off New Zealand, July 8, 1874; kit, 40° 28' S.,long. 177° 43' E.; depth, 

 1100 fathoms; bottom temperature, 37° - 2 F. ; blue mud. 



