441 
I. II. iiL IV. V. VI. VII. vm. 
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 
The Antennæ (fig. 4, <7; fig. 6) are siender and a little more 
than one third as long as the antennulæ. They consist of four 
joints. The first joint is considerably thicker than long, the second 
somewhat shorter than the two distal ones together, and the terminal 
joint a little shorter than the third. No seta exists on the three 
proximal joints; the fourth joint terminates in a seta which is as 
long as the fourth, the third and the first joint together, somewhat 
curved, very thick at the base and gradually tapering towards the 
acute end. At the base of this seta I have discovered only one 
rather short and thin hair. The exopod (e) is very small, oblong, 
exarticulate, inserted at the end of the second joint and adorned 
with two setæ, one of which is terminal. 
The Mouth. Labrum and hypopharynx constitute together a 
sipho which encloses the mandibles and originates between the 
insertions of the antennæ. The sipho is seen vertically from in 
front in fig. 7; fig. 8 show^s it from the side; in fig. 4 it is shown 
in an oblique position and therefore shorter in proportion to its 
breadth than in fig. 7. It is almost as long as the antennæ, twice 
as long as broad, oblong-ovate, but with the distal end produced 
into a short tube; besides it is considerably compressed (comp. fig. 8 
with fig. 7), with the labrum very deep and strongly vaulted in 
front. The labrum is slightly shorter than the hypopharynx and 
cut off‘ transversely; the hypopharynx is also cut off, but each 
lateral angle is produced into a small triangular projection which is 
bent backwards. The mandibles have no palp; they are exceedingly 
difficult to study: as far as could be observed their distal portion 
is exceedingly siender, without teeth, and the outline of their proxi¬ 
mal part could not be discerned with certainty. 
The Maxillulæ (first pair of maxillæ) are small (fig. 4, g). 
The drawing show^s what I have been able to see on the'prepara- 
tion. I observed a very narrow plate which tapers distally and 
