Crossword-Solution: DECAPODA 8 letters, 1 clue 🏆 scrabble score: 14

The existing deficiencies were the more difficult to supply, because, as Van Beneden remarks with regard to the Decapoda, from the often incredible difference in the development of the most nearly allied forms, these must be separately studied—usually family by family, and frequently genus by genus—nay, sometimes, as in the case of _Penëus_, even species by species; and because these investigations, in themselves troublesome and tedious, often depend for their success upon a lucky chance.

The most important peculiarities which distinguish this Zoëa-brood from the adult animal, are as follows:— The middle-body with its appendages, those five pairs of feet to which these animals owe their name of Decapoda, is either entirely wanting, or scarcely indicated; the abdomen and tail are destitute of appendages, and the latter consists of a single piece.

The tracing of the development in the egg is rendered difficult by the circumstance, that the Mantis-shrimps do not, like the Decapoda, carry their spawn about with them, but deposit it in the subterranean passages inhabited by them in the form of thin, round, yellow plates.

Mecznikow has recently observed the development of _Nebalia,_ and concludes from his observations “that _Nebalia,_ during its embryonal life, passes through the Nauplius- and Zoëa-stages, which in the Decapoda occur partly (in _Penëus_) in the free state.” “Therefore,” says he, “I regard Nebalia as a Phyllopodiform Decapod.” The youngest larvæ [of the Phyllopoda] are Nauplii, which we have already met with exceptionally in some Prawns, and which we shall now find reproduced almost without exception.

And in the same way among the Ostracoda, the _Cypridinæ,_ which I find possess a heart, place themselves side by side with _Cypris_ and _Cythere_ which have no such organ.—Or to the respiratory apparatus? Milne-Edwards did this when he separated _Mysis_ and _Leucifer_ from the Decapoda, but he himself afterwards saw that this was an error.