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 CRUSTACEANS impracticable task. Dr. Sorby reports the curious parasitic copepod, Lerneonema spratta (Sowerby), 'found on the eyes of sprats caught in the open water off Essex,' and the sessile cirripede ' Balanus punctatus ' as ' common all along the coast, and especially in the estuaries, where the number of larvae is sometimes so great that in a few days the bottom of a yacht is completely covered with the young shells.' In regard to ' B. punctatus ' a reference to Darwin's celebrated work shows that the name is rather deeply afflicted by chronic vagueness. Under his account of B. balanoides (Linn.) Darwin explains that this species, 'in its corroded and therefore punctured state, is certainly the B. punctatus of most British collections ; but,' he adds, ' I do not believe it is the B. punctatus of Montagu, which I have scarcely any doubt is the Chthamalus stellatus so often found in the southern shores of England, and even in some of the best arranged collections, mingled with our present species.' 1 Under C. stellatus (Poli) he says, ' On the coast-rocks of the southern shores of England it is, in parts, even more numerous than the Ba/anus balanoides, with which it often grows mingled. As already stated, it is often con- founded in British collections with this species of Balanus under the name of B. punctatus that Montagu had this Chthamalus in view when describing his Lepas punctatus is certain, from his original specimen in the British Museum, but whether this was the case with his predecessor Pulteney in the Dorset Catalogue 1 do not feel so sure.' 1 As Dr. Sorby has kindly furnished me with some of his specimens, I can testify that they include Chthamalus stellatus, and, as I believe, also Balanus crenatus, Bruguiere, which has a calcareous basis, whereas that of B. balanoides is membranous. On the whole it may be concluded that there are at least three species of Thyrostraca or Cirripcdes on the Essex coast. Apart however from Dr. Sorby's interesting manuscript notes, the crustacean parasites of fishes and of many other aquatic animals, the barnacles, stalked or sessile, fixed or floating, and several important groups of the Malacostraca have hitherto had few records or none by which their relative prominence in this locality can be determined. Some future faunistic description of Essex will show, certainly that they are not absent, probably that they are present in abundance. 1 Balmidae, Ray Soc. pp. 208, 456 (1854). 219