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Updated: June 10, 2025
Dr. The comparison of the Leptus with the Nauplius, or pre-Zoëal stage of Crustacea, is much more natural. But here we are met with apparently insuperable difficulties. It is evident that the Leptus fundamentally differs from the Nauplius and begins life on a higher plane. We reject, therefore, the Crustacean origin of the insects.
A little water flea was described as a separate genus, Nauplius, before it was known to be the larva of a higher water flea, and so also Leptus was thought to be a mature mite. Accordingly, we follow the usage of certain naturalists in dealing with the Crustacea, and propose for this common primitive larval condition of insects the term Leptus.
A similar development must have been once passed through by the primitive ancestor of all Malacostraca, probably differing from that of our Prawn, especially in the circumstance that it would go on more uniformly without the sudden change of form and mode of locomotion produced in the latter by the simultaneous sprouting forth and entering into action in the Nauplius of four and in the Zoea of five pairs of limbs.
These are the antennae and mandibles. The egg-membrane now bursts, before any internal organ, or even any tissue, except the cells of the cutaneous layer, is formed. The young animal might be called a Nauplius; but essentially there is nothing but a rough copy of a Nauplius-skin, almost like a new egg-membrane, within which the Mysis is developed.
Nauplius of Tetraclita porosa after the first moult, magnified 90 diam. The entire series of Nauplius-stages which are passed through by the free Copepoda, are in this case completely over-leapt. Some ascribe to them a very subordinate position among the Copepoda; as Milne-Edwards . In direct opposition to this notion of his father's, Alph.
Having reached the Nauplius, the extreme outpost of the class, retiring furthest into the gray mist of primitive time, we naturally look round us to see whether ways may not be descried thence towards other bordering regions.
In the great class of the Crustacea, forms wonderfully distinct from each other, namely, suctorial parasites, cirripedes, entomostraca, and even the malacostraca, appear at first as larvae under the nauplius-form; and as these larvae live and feed in the open sea, and are not adapted for any peculiar habits of life, and from other reasons assigned by Fritz Muller, it is probable that at some very remote period an independent adult animal, resembling the Nauplius, existed, and subsequently produced, along several divergent lines of descent, the above-named great Crustacean groups.
These quit the egg with an unsegmented ovate body, a median frontal eye, and three pairs of natatory feet, of which the anterior are simple, and the other two biramose in fact, in the larval form, so common among the lower Crustacea, to which O.F. Muller gave the name of Nauplius.
Arabian commanders and supercargoes were always employed in their ships, from their experience in the navigation: the imports of Rhapta were, lances, principally manufactured at Moosa; axes, knives, awls, and various kinds of glass: the exports were, ivory, inferior to the Aduli ivory, but cheap, and in great abundance; the horns of the rhinoceros, tortoise shell, superior to any of this coast, but not equal to the Indian; and an article called Nauplius, the nature of which is not known.
And on the left of the vestibules is a building with paintings; and among those that time has not destroyed are Diomedes and Odysseus the one taking away Philoctetes's bow in Lemnos, the other taking the Palladium from Ilium. Among other paintings here is Ægisthus being slain by Orestes; and Pylades slaying the sons of Nauplius that came to Ægisthus's aid.
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