10 Alf Wollebæk. [No. 12 
In contradistinction to the 2nd maxilliped this gnathopod has 
a very long third joint (isehium, 3), which is longer than any of 
the other joints. [In the 2nd gnathopod meros was the longest 
joint]. There is å dentated crest (Orista dentata) along the whole 
upper surface of the ischium (fig. 2 B, V). 
Meros, which is about half as long as isehium, has its inner 
edge armed with some anteriorly-directed spines, two large ones 
and one rather smaller, as well as with some considerably smaller 
spinules. | 
The 5th and 6th joints (CUarpos and propodos) are of about the 
same length, each of them being shorter than meros: they are 
together of about the same length as isehium. The 7th joint 
(Dactylos) is only half as long as the preceding joint. All the 
joints are furnished with setae, which are longest and most dense 
on the inner edge. 
Eephysis (exognath) consists like that of the foregoing gnathopod 
of åa peduncele (a») and å multartieulated lash (with about 14 artieul- 
ations (a1). "The pedunele is of about the same length as the ischium. 
The lash, almost equally long, projects slightly beyond the meros 
of the stem, and is distally provided with several long thin setae. 
Mastigobranchia (20) is comparatively small and narrow, with 
long setae on its inner edge and a poorly developed podobranchia 
on its outer edge. Two well-developed arthrobranchiae appear, 
considerably larger than the mastigobranchiae, but a good deal 
smaller than the succeeding pair of arthrobranchiae on the 1st pair 
of pereiopods. 
1st Pereiopod (fig. 1, IV) is the longest and strongest of 
five pairs the of pereiopods. 
The pereiopod on the right side is as. å rule considerably more 
powerful than that on the left. [In one of the specimens examined 
the opposite was the case, in another the right chela was regene- 
rated and on that account smaller than the left]. The right perei- 
opod in å specimen 57 mm. long measured 40» mm., of which 
propodos celaimed 17 mm., carpos 61/> mm., meros 12 mm., and the 
remaining joints between them 5 mm. 
Isehium is furnished along both edges with small spines, one 
of which on either side of the distal portion is larger than the 
others. Meros has more numerous long sharp spines than any of 
the other joints. In the middle of the lower edge are one, or some- 
