222^ Miscellaneous. 



fly, struck out her oars, and thereby was rapidly impelled through 

 the fluid. 



The figures of Desmarest (tab. 50.) and Yarrell (Brit. Fish., vol. ii. 

 p. 399.) are very characteristic of this species, but the great beauty 

 exhibited in the specimen before me is at the same time not shown, 

 perhaps in consequence of the upper side of the female not being re- 

 presented — this consists in its being closely spotted with very dark 

 green along the central part of the body for two-thirds posteriorly 

 commencing a little above the ovary in the form of a head, and ex- 

 tending to the posterior portion ; the rest of the upper side of the 

 body being of a very pale yellowish green hue and semi-transparent 

 as described, the part thus spotted is well defined, and is strikingly 

 of the form of a coleopterous insect, which the Argulus in another 

 point of view resembles, when the two sides of the greenishly trans- 

 parent •* boucliers" are thrown a little apart, as we see the elytra 

 of the insect. I was further reminded of the resemblance when at- 

 tempting to remove it, as in holding firmly l)y the suckers, the body 

 was drawn in, and the " boucliers" elevated quite above it. Its mo- 

 tion through the water seems equally rapid whether it be on the up- 

 per or under side, or swimming retrally — it frequently moved along 

 the surface with its back downwards, and was wholly immersed ex- 

 cept the suckers, which were thrown either on a line with the water 

 or quite above it, and thus would the animal occasionally remain 

 quiescent for a short period. 



The constant motion of these organs (visible to the naked eye) in 

 addition to the rapid play of the feet, impart much life to the ap- 

 pearance of the Argulus, and present not the same aspect for two 

 continuous seconds of time, whether the body be at rest or other- 

 wise. They — i. e. the marginal row of minute suckers, which ap- 

 pear as a dark line round the disk in figures of the species — are fre- 

 quently drawn together to the centre of the disk, exhibiting a dark 

 point not larger than the eye. 



The eye itself, under the lens or microscope, exhibits constant 

 motion, and even to our unassisted vision 

 its red colour — that of the lady bird, Coc- 



cinella septempunctata — is apparent ; when . v^^ 



magnified it looks black where the lines ' @ ^^y \ 



and dots are, red elsewhere. 



After having been about four or five hours in the salt water, and 

 displaying its wonted activity to the last, the specimen was lost 

 during my absence from the room. I had intended to observe how long 

 it — a freshwater species — would live in salt water, but though foiled 



