1524 THE VOYAGE OF H.M.S. CHALLENGER. 



extremely minute furring of the hind margin, the apical process large, longer than the 

 base, almost as long as the hand, almost acute, finely pectinate at the upper part of 

 the hind margin, the lower part having nearly twenty teeth, the front or inner margin 

 smooth at the base, then armed with fourteen teeth, which are larger than those on the 

 opposite side ; the hand shaped and placed as in the first gnathopods, but with the hind 

 margin near the base finely pectinate, and below more strongly with about twenty small 

 unequal teeth ; the finger not half the length of the hand. 



First Per&opods. — First joint similar to that of the second gnathopods, but narrower 

 above and more widened below ; the second joint rather longer than broad ; the third 

 with narrow neck, then much widened and distally scarcely narrowed, the front margin 

 convex, with the apex rounded ; the fourth joint narrower than the third and very 

 slightly longer, smooth, a little curved, the distal margin finely pectinate ; the fifth 

 joint narrower than the fourth, of about the same length, finely pectinate along the 

 hind margin, within which there are also five minute spinules ; the finger curved, scarcely 

 a third the length of the fifth joint. 



Second Perseopods. — The first and second joints narrower than in the preceding 

 pair, the three following joints longer and narrower; the third joint strongly bent, 

 the front margin convex, the hinder concave, both smooth ; the fourth joint a little 

 longer and narrower, also smooth, slightly curved ; the fifth joint slender, almost as long 

 as the fourth, with six microscopic spinules along the slightly furred hind margin and 

 some very fine pectination at the distal extremity ; the finger less than a quarter of the 

 length of the first joint. 



Tliird Perseopods. — The side-plates with a curved tongue-like backward directed 

 process on the inner side. The first joint a sort of oblong or long oval, about two and 

 a half times as long as the greatest breadth, which is rather below the middle, not 

 quite equal in length to the following joints together, the front margin nearly straight, 

 with a little shallow serration of the lower part, the surface adjoining the front margin 

 marked with seven or eight more or less parallel longitudinal lines, the distal margin 

 somewhat flattened, the surface above this marked with some little oblique curved lines ; 

 the second joint longer than broad, so placed as not to be able to reach either the distal 

 or the hinder margin of the large first joint ; the third joint more than twice as long- 

 as the second, the hinder apex a little produced, almost acute, pectinate, the front 

 margin at first smooth, then feebly and by degrees more strongly pectinate ; the fourth 

 joint about once and a half as long as the third, a little narrowed distally, all the front 

 margin pectinate ; the fifth joint much narrower than the fourth, almost as long, a little 

 bulb forming the hinge, the hind margin smooth, produced into a small apical tooth, 

 the whole front margin pectinate, the teeth become smaller towards the narrow apex, of 

 which the margin is also finely fringed ; the finger about a fifth of the length of the fifth 

 joint. 





