376 LOWER INVERTEBRATES. 



lids, and the cornea is perforated so that the salt water bathes the lens ; the siphon is 

 held by four bands and contains an internal valve (probably the homologue of the 

 mesopodium). 



The typical genus is Ommastrep/tes, of v^hich one species, 0. iUecihrosus, is the 

 most common squid north of Cape Cod, though further south it is less common, and 

 replaced by Loligo pedlei. From an economic point of vievir it is a very important 

 species, for its distribution is coincident with that of the cod-fisliery, in which it is 

 used as bait. They swim in large schools, and are frequently found following schools 

 of young mackerel and herring, on wliich they feed. They usually swim backwards, 

 with the ease and grace of a trout, and a school of them furnishes a beautiful sight, 

 their color changing instantly to accord with the bottom over which they pass. They 

 are largely nocturnal, though they are seen in large numbers in the daytime. In the 

 morning, on Cape Ann, the flats will sometimes be found covered by specimens left by 

 the retreating tide during the night. When stranded they can do but little to help 

 themselves. Their usual recourse is to begin to pumjj water through the siphon, but this 

 forces them farther on the beach as frequently as it aids them in their escape to deeper 

 water. Left on the shore, and exposed to the air, they quickly die. In confinement 

 they usually live but a short time, as they are very timorous and dart backward with 

 great velocity on the slightest alarm. In doing this they almost always strike the 

 hinder end of the body against the walls of the tank in which they are kept, inflicting 

 injuries which soon prove fatal. At times I have known them to leap from the tank 

 in which they were kept, clearing the sides, which extended eight inches above the 

 water. 



In confinement I have watched them capture small fishes. They advance stealthily 

 towards the proposed victim by undulations of the fins, when they suddenly seize it by 

 means of the tentacular arms, and kill it by biting a piece out of the back of the neck 

 with their powerful jaws. In their natural freedom, according to Professor S. I. Smith, 

 they dai't suddenly backward amongst the school of young fish, and then suddenly turn 

 obliquely to the right or left to seize their victim. 



In some places they aie caught for bait by driving the school on shore ; at other 

 times by the use of nets and pounds. This latter method is the one most adopted by 

 the fishermen on Cape Ann. In Newfoundland 'jigging' is the process employed. 

 A jig is a bit of lead armed with hooks radially arranged, which is let down from the 

 boat and kept constantly moving up and down. This in some way exerts a fatal 

 fascinating power upon the squid, which seizes it, and, becoming entangled in the 

 hooks, they arc quickly drawn to the surface. In Japan an allied species is caught in 

 a similar manner. The number of squid used annually in the cod fishery is almost 

 beyond computation ; a small vessel in six weeks will sometimes use eighty thousand 

 squid. For the purposes of bait some are kept fresh, and others are salted or pickled 

 in brine. As would be supposed from their being used as bait, many fish are fond of 

 squid, and not unfrequently schools of these molluscs which are pursuing young 

 mackerel are in turn pursued by older fish of the same species. 



In the older works many allusions are made to huge marine monsters, the descrip- 

 tion and figure of Pontoppldian being most frequently copied. In all of these 

 accounts, the animal jDartakes of the nature of a squid or poulpe. One of these early 

 accounts, which relates to a specimen stranded on the coast of Ireland, is more accu- 

 rate than most, and is withal so quaint that it deserves to be quoted here. It was 

 published in 1673, and is quoted from Prof. Verrill. 



