ETC. 439 



of Cancer irroratus, (p. 312, Plate YlII, figs. 37, 37a,) and of Flaty- 

 onichus in the zoea and megalops stages, were taken in vast numbers, 

 especially in bright sunshine, together with similar larv« of many 

 other species. The larvii? and young of the lobster {Plate IX, figs. 38, 

 39) were also abundant in mid-summer. The numerous specimens ob- 

 tained have enabled Mr. S. I. Smith to describe the interesting meta- 

 morphoses of our lobster, which were entirely unknown before. The 

 young swim actively at the surface, like a shrimp, until mure than half 

 an inch long. The larviie and young of the various species of shrimps 

 are also abundant. The curious larvie of SquiUa emjmsa (Plate YIII, 

 fig. 36) were often met with. 



Several species of Araphipods are also common at the surface. The 

 most abundant were Calliopius Iceviuscuhis^ of which Mr. Y. N. Edwards 

 also took numerous large specimens in February and March ; Oammarus 

 natator, which was usually common, and occurred in immense numbers 

 August 10 and on several other occasions j and a Hi/peria, which infests 

 several species of large jelly-fishes, and also swims free at will. The 

 Fhronima is a related genus, but is very remarkable for its extreme 

 transparency, which renders it almost invisible in water. Idotea irro- 

 rata (p. 316, Plate Y, fig. 23) and L rohusta, Plate Y, fig. 24) were 

 very common among masses of fl^oating eel-grass and sea- weeds, and 

 the latter Was also very often found swimming entirely free. 



A species of SappMrina (Plate YII, fig. 33) was found in great num- 

 bers among iSaij^te, off Gay Head, on several occasions, early in Septem- 

 ber. This is one of the most brilliant creatures inhabiting the sea. It 

 reflects the most gorgeous colors, blue, red, purple, and green, like fire- 

 opal, although when seen in some positions, by transmitted light, it 

 is colorless and almost transparent. Under the microscope, w^hen 

 living, it is a splendid object, whether seen by transmitted or reflected* 

 light, the colors constantly changing, as it is turned in different posi- 

 tions. AYhen seen beneath the surface of the sea, in large numbers, 

 the appearance is very singular, for each one as it turns in the right po- 

 sition reflects a bright gleam of light, of some brilliant color, and then 

 immediately becomes invisible, and these scintillations come from dif- 

 ferent directions and various depths, many of them being much farther 

 beneath the surface than any less brilliant object could be seen. In 

 some cases one or more were found in the branchial cavity of Salpce^ 

 but whether this is normal or accidental was not determined. 



The species of Argulus are parasitic on the exterior of fishes, but we 

 found at least three species swimming free at the surface. It is, there- 

 fore, probable that they are able to leave their hosts for a time, and 

 thus to migrate from one fish to another. The species of Caligus are also 

 parasites on fishes, to which they firmly adhere, but the half-grown 

 young of one species was taken at the surface in the to wing-nets. 



Numerous species of Annelids, in the larval and young stages, were 

 taken at the surface, but many of them have not yet been identified. 



