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



overhangs a narrow area posterior to the united cervical grooves ; a single spiuule 

 (occasionally absent) is present on each branchial region, placed behind the cervical 

 groove and near the confines of the cardiac area. The lateral margin of the carapace is 

 armed with about six spines, only the first of which reaches any considerable size, two 

 being situated in front of the anterior division of the cervical groove. The posterior 

 margin of the carapace is raised, and bears two sj)ines. 



The chelipedes are moderately long, and the merus, carpus, and propodus are covered 

 with large almost smooth scales, some of which, on the inner surface of the same joints, 

 more especially the merus, are produced into spines ; in females and young males the 

 chelijjedes are narrow and cylindrical, whereas in adult males the hand is slightly 

 dilated; the propodus is about two and a half times the length of the carpus (in adult 

 males it is somewhat longer) and comparatively few spines are present on the inner 

 surface ; the fingers are long and slender, being about two-thirds the length of the palm, 

 and the tip of the dactylus fits in between two small teeth at the apex of the immobile 

 finger ; in females the fingers are straight and in contact throughout, with their opposed 

 edges finely crenated, while in adult males both — but especially the immobile finger — 

 show a prominent bulging which gives rise to a basal hiatus, and a single tubercular 

 tooth is present on the inner margin of each along with a dense clothing of stiff hairs. 

 The ambulatory limbs are similar to those of Municla normani, but the scales are more 

 strongly developed and the dactyli are slightly longer. 



The eyes are of large size, and somewhat compressed, and as in the last two species 

 distinctly reniform in shape. The antennal peduncle is pubescent, and the anterior pro- 

 longation of the first joint is short. The ischium and merus of the external maxillipedes 

 are both squamose externally and strongly pubescent ; the inner margin of the former is 

 prolonged distally into a slender acute spine, while the latter joint has a slightly larger 

 spine situated near the middle of the same margin. 



The second, third, and fourth abdominal segments are armed as in Municla normani, 

 the two lateral spinules on the fourth segment being occasionally obsolete ; the dorsal 

 surface of the fifth and sixth segments, telson, and last pair of appendages, is covered with 

 scales which are of smaller size and more numerous than in Municla normani. 



This species is nearly related to Municla normani, from which it is distinguished by 

 the difi"erent armature of the cardiac and branchial areas of the carapace, the greater 

 development of the striae, the form of the chelipedes, and other less important distinctions. 

 The cardiac spine is uniformly well developed even in very young individuals. The most 

 important sexual difi'erence has abeady been referred to in treating of the chela. 



Breadth of carapace (of an adult male) 17 mm., length of body 45 mm., of carapace 

 16"5 mm., of rostrum 6'3 mm., of chelipede 85 mm., of chela 36 mm., of first ambulatory 

 leg 58 mm. Females are apparently of slightly smaller size than males. 



Habitat. — Station 219, north of Papua; depth, 150 fathoms; bottom, coral mud. 



