REPORT ON THE CRUSTACEA MACRURA. 41 



Length, 21 mm. (O'S inch). 



Habitat. — Station 194a, off Banda, September 29, 1874 ; lat. 4° 31' 0" S., long. 

 129° 57' 20" E.; depth, 360 fathoms; volcanic mud. Associated with Cheiroplatea 

 cenobita. 



Carapace one-third the length of the animal, laterally compressed, more so anteriorly 

 than posteriorly ; lateral walls deep, inferiorly compressed, increasing from the frontal 

 margin obliquely backwards with an imperfect anteroinferior angle ; posterior projecting 

 a little beyond the dorsal margin of the carapace. The dorsal surface is arched a little 

 over the gastric region, and projects forwards in the form of a flat triangular rostrum 

 which has a slight elevation in the median line, while on the inferior surface of the 

 rostrum, a similar but more important ridge exists as a projection between the eyes. 

 The margins of the rostrum are smooth, except under a magnifying power, when they 

 appear slightly serrate. 



The first somite of the pleon is short and divided into an anterior depressed portion, 

 which is capable of being covered by the carapace, and an elevated posterior portion. 



The four following somites are subequally long, and support laterally large and deep 

 coxal plates, the infero-anterior angle of which is rounded to a posteriorly directed 

 oblique line, whereas the infero-posterior angle is produced to a sharp point which 

 becomes less prominent on each somite posteriorly, and scarcely exists in the fifth. The 

 sixth somite is shorter than the preceding, but nearly as broad ; it has less important coxal 

 plates, and the posterior margin is excavated to receive the articulated joint of the caudal 

 pleopoda. The telson is square, the posterior margin being fringed with short cilia. 



The eyes are small and project on each side, but do not reach beyond the base of the 

 rostrum. 



The first pair of antennas has the peduncle extending considerably beyond the 

 rostrum. The first joint is short, not reaching to the extremity of the rostrum, and is 

 slightly excavated on the upper surface to receive the eye ; the second joint is shorter than 

 the first, and reaches beyond the rostrum; the third is shorter than the second, and supports 

 two unequal flagella, the primary or upper being one-fourth longer than the lower. 



The second pair of antenna? has the peduncle reaching beyond the extremity of 

 that of the first ; its third joint is externally produced to a long sharp tooth or 

 stylocerite, between which and the base of the fourth joint stands a strong sharp movable 

 spine, the homologue of the scaphocerite attached to the second antennae of most 

 Macrura — it is sharp, spine-like, and free from hairs or cilia ; the fourth joint of the 

 peduncle is very long, and reaches nearly to the extremity of the scaphocerite, whereas 

 the fifth is shorter than the fourth, reaches beyond it, and supports a slender flagellum 

 that makes the antennas about half the length of the animal. 



The oral appendages do not differ very materially from those of Paraxius. The 



(ZOOL. CHAIX. EXP. — PART LII. — 18SG.) Fff 6 



