104 Dr. F. Miller on the Metamorphoses of the Prawns. 
XI.—On the Metamorphoses of the Prawus. (First Memoir.) 
By Dr. Frirz Miuuer of Desterro*. 
[Plate IV.] 
Mitne-Epwarps indicated, as probably the larva of Peneus, a 
small Crustacean which had previously been referred to the 
Schizopoda as forming the genus. Cryptopus of Latreille. I ob- 
served several species of small Crustacea approaching still more 
closely to the Schizopoda, and agreeing with Cryptopus and 
Peneus in the possession of three pairs of cheliform feet, and 
have been able to trace them back to Mysis-forms destitute of 
chele, thence to the form of a Zoéa, and one species still further 
to a Nauplius-form, and consequently to that fundamental young 
form which unites the Rhizocephala and Lerne with the Cirni- 
pedes and the numerous group of the Cyclopide. 
Of the Zvéa-form five different species were observed, and 
some of them pretty plentifully during the whole summer ; the 
unaltered Nauplius-torm, probably the same in which the animal 
escapes from the egg, came under notice only once (on the 18th 
December) +. 
The body of this youngest larva (PI. IV. fig. 1) is destitute of 
segments, pyriform, 0-4 mill. in length, rounded, and 0-2 mull. 
in breadth in front, and diminished behind to 3th of the length 
of the body, truncated, and slightly emarginated. Near the 
anterior margin stands a small, black, sharply defined eye. The 
posterior margin bears on each side a strong straight bristle, of 
half the length of the body, and near this a short spine. From 
the lower surface of the body spring six slender feet, furnished 
with long sete, of which the anterior and intermediate attain 
four-fifths and the posterior about half the length of the body. 
The anterior are placed close to the frontal margin, the inter- 
mediate pair immediately behind these, and the posterior about 
the middle of the body. The anterior are simple, the intermediate 
and posterior biramose ; the posterior branch appears to be the 
immediate continuation of the stem, and is stronger and, in the 
hinder feet, also much longer than the anterior branch. -No 
distinct joints are to be detected in the feet, but indications of 
four or five jomts may be seen in the posterior branch of the 
intermediate feet. A strong bristle, as long as the body, stands 
with some shorter ones at the apex of the anterior feet ; the inter- 
* Translated by W.S. Dallas, F.L.S., from Wiegmann’s ‘ Archiv,’ 1863, 
p- 8. 
+ This proves that, at least at the breeding-season, the parents do not 
reside in the vicinity of the shore, as otherwise the youngest larvee must 
have been the most abundant. A species nearly allied to Peneus Caramote, 
which is frequently eaten here under the name of Camarao occurs sparingly 
in the market in summer, and scarcely ever above the middle size. 
ee 
