THE LANCELET. 297 



writes Mr. Couch, " this fish had a very evident though diaphanous fin, extending from near 

 the snout, round the extremity of the tail, which it encircled in the manner (if the same organ 

 in the eel, and terminating at the vent. This specimen was not found in a pool, but lay buried 

 in a small quantity of sand, at about fifty feet from the receding tide ; and on turning over a 

 small, flat stone that was on the sand, the tail of the flsh appeared exposed. 



"When moved, it exhibited signs of great activity, so that the head could not readily be 

 distinguished from the tail ; and as there can be no doubt that the fish had sought the shelter 

 of the sand in which it was found, there is little question that mud is its usual habitation ; a 

 circumstance still more probable by its want of eyes. 



"It was discovered after a heavy storm that had torn it from its native situation, which, 

 from its rarity, we may suppose to be in deep water. Some time later, I obtained two other 

 specimens, which had been thrown up by a tempest. The largest measured two inches and 

 three-tenths in length, which enabled me to discern still more of the internal structure of 

 this fish." 



Several other specimens have been obtained, mostly scraped up in the dredge. On the coasts 

 of the Mediterranean this fish is not uncommon ; and the following interesting account of some 

 of its habits is given by Mr. Wilde, in his narrative of a voyage to the Madeiras, Teneriffe, and 

 along the shores of the Mediterranean. After describing the general appearance of the fish, 

 he proceeds as follows : — 



"These little animals had a power of attaching themselves to each other in a remarkable 

 manner, sometimes clustering together, and at others forming a string six or eight inches long ; 

 the whole mass seemed to swim in unison and with great rapidity, going round the vessel in a 

 snake-like form and motion. They adhered to each other by their fiat sides, when in line, the 

 head of one coming up about one-third on the body of the one before it ; no doubt those sides 

 are of use in forming this attachment. 



"The mouth was a circular disc surrounded by cilia that continued in constant motion. 

 When put into a tumbler of water it moved round the glass, and although no eyes -were per- 

 ceptible, it carefully avoided the finger or any substance put in its way, stopping suddenly, or 

 turning aside from it. Both these animals, when taken out of the water, kept up a strong, 

 pulsatory motion for some time. The small one by this means pumped out of its interior a 

 quantity of air and water ; and they could be seen coming to the surface to inhale, and a 

 globule of air was observed floating through th - internal cavity. In the larger species the 

 internal tube was perfectly distinct and of a blue color. When put into spirits and water it 

 died almost immediately, and turned opaque; a number of circular bands also appeared on it." 



The general aspect of the Lancelet is not unlike that of the leptocephalus already described, 

 the delicate, transparent body, and the diagonal arrangement of the muscles causing a con- 

 siderable resemblance between the two. But the leptocephalus is at once distinguished by its 

 head, which, although very small in proportion to the body, is yet perfect, possessing well- 

 developed eyes, gill-covers, jaws, and teeth, whereas the Lancelet has no particular head, and 

 neither eyes, gill-covers, jaws, nor teeth. 



Vol. in.- 3S. 



