98 Dr. A. Philippi’s Zoological Notices. 
flagellum is vaulted exteriorly with a keel, interiorly grooved, 
serrated and finely ciliated at the margins, so that they close 
completely. The canal continues in the stalk (Stiel), but here 
only the upper half is formed by the stalk, and is closed in- 
feriorly by the scales of the outer antennz, as it seems the 
upper lip divides the canal, which then proceeds right and left 
to the branchiz. As far as I am aware, no similar formation 
exists among the Crustacea. 
The feet are exactly as in the other species of Peneus; all 
have at the base a filamentary process corresponding to the 
palpi of the foot-jaws; the three first pair have pincers 
(chele), and increase from the first to the third in length, 
which increase is effected, namely, by the growth of the tibia. 
The fourth pair of feet is as long as the second, the fifth as 
long as the third. The exterior footjaw is nearly twice as 
long as the first pair of feet, and consists of rather cylindrical 
and capillary joints. 
The figure Pl. IV. fig. 3. will render a more detailed de- 
scription superfluous. 
Puate III. Fig. 12. Nauplius ciliatus, Phil. Sixty times magnified. 
a. Natural size. 
Prate III. Fig..13. Laophonte cornuta, Phil. Female, sixty times mag- 
nified. 
Prate IV. Fig. 1. Psamathe longieauda, Phil. Magnified sixty times. 
«x. Natural size. 
a. The outer foot-jaw magnified 150 times. 
Puate LV. Fig. 2. Thyone viridis, Phil. Examined with a power of sixty. 
a. Nat. size. 
b. The outer foot-jaw, with its palpus more strongly magnified. 
d. The second pair of antenne. 
e. The mandible, near it a foliaceous fringed organ similar to the 
one designated by g: should it be considered as branchia? 
f. The one foot-jaw. 
N.B. The maxillz could not be represented on this scale. 
Pirate IV. Fig. 3. Peneus siphonoceros, Phil. Nat. size. 
a. Cross section of the tube formed by the flagella of the upper 
antenne, magnified. 
6. Pontarachna punctulum, Ph.,an Hydrachnidan of the Ocean. 
(Pl. IV. fig. 4. and 5.) 
Hitherto Hydrachnz have been found solely in fresh water, 
but I have met with, and not at all unfrequently in the bay 
of Naples, a spider belonging to this division of the Arachnida 
likewise in sea-water. Unfortunately it is so minute, scarcely 
3rd of a line in length, that I have not been able to recog- 
nise all its parts, although I have frequently examined several 
specimens. The body is rather globular, anteriorly somewhat 
acute, quite bare. Its colour is brownish-yellow, more fre- 
