898 MR. J. Y. JOHNSON ON NEW CRUSTACEANS. [NoV. 28, 



distance behind the posterior rostral tooth there is a tooth on the 

 median crest of the carapace. The under edge of the rostrum is 

 destitute of teeth. There is a fringe of hair in the neighbourhood 

 of the rostral teeth, and on the under edge of the rostrum as far as 

 the upper fringe extends. At the front border of the carapace there 

 are four small teeth — one over the exterior base of each of the supe- 

 rior antennae, and one over the base of each of the inferior antennae. 

 Each of these teeth forms the termination of a ridge ; and of these 

 ridges the two nearer the lateral margins of the carapace are higher 

 and longer than the other two. About the middle of the height of 

 the carapace there is another ridge on each side, but it does not ex- 

 tend backwards beyond the middle of the length of the carapace. 

 Between the two principal ridges the carapace is concave ; and there 

 is a furrow on the upperside of the exterior ridges ; these furrows 

 extend backwards to about the middle of the length of the carapace, 

 and they then bend obliquely downwards towards the lateral borders. 

 At the bend another furrow commences, which widens backwards and 

 upwards until it reaches nearly to the posterior border of the cara- 

 pace. An intramarginal furrow extends round the carapace, except 

 in front ; and the sides have a broad membranous border. 



The eyes are black, round, large, and of greater diameter than the 

 stalk. The eye and stalk together are less than half as long as the 

 peduncle of the superior antennae, and do not reach so far as the 

 base of the filament of the inferior antennae. 



The basal joint of the superior antennae is excavated to receive the 

 eye ; there is a blunt recumbent tooth on the external edge of the 

 excavation, near the base, and a second tooth, which is sharp, near 

 the distal extremity ; the inner edge is thickly set with hair, and 

 bears a small tooth near the base. The third jouit is shorter than 

 the second, which is cylindrical, and the second than the first. The 

 lower of the two filaments is very long, being about equal to the 

 total length of the animal ; whilst the other is compressed and very 

 short, being much shorter than the carapace. The peduncle of the 

 inferior antennae is cylindrical ; and its single filament is slender and 

 very long, being much longer than the animal. The antennal scale 

 or lamellar palp extends beyond the peduncle of the superior an- 

 tennae ; on its upper face there is a deep longitudinal groove near 

 the outer margin, and a small tooth on the outer border near the 

 extremity ; the inner border is fringed with hair. The joint to which 

 this scale is attached is stout, and carries a strong tooth on its under- 

 side. 



The external jaw-feet are large and pediform ; they are more 

 than twice as long as the multiarticulate ciliate palp, and they reach 

 to the distal extremity of the lamellar palp of the inferior antennae. 

 The next pair of jaw-feet are much shorter, and are only half as long 

 as their \erj elongate multiarticulate ciliate palps. The third joint 

 of these jaw-feet is much compressed and broad. Each of the jaw- 

 feet of the two outer pairs is furnished with a ciliate lamellar appen- 

 dage at the base ; the remaining three pairs of jaw-feet are short, 

 and are furnished with several lamellar appendages. 



