3774 The Zoologist — November, 1873. 



[The genus Ommastrephes of D'OrLigny comprises those auimals so 

 familiar to fishermen, and indeed to all " toilers of the sea," or visitors of 

 the sea, by the popular names of "squids," "flying squids," "cuttles" or 

 "arrows"; every one also knows their single bone or "pen," a semipellucid 

 flattened object dilated at its attenuated and almost membranous margin, 

 and altogether resembling horn rather than bone. These squids are 

 distributed over the entire world of waters, and the work of D'Orbigny 

 shows us how they and their allies the Ammonites and Nautilites swarmed 

 in the oceans of bygone times. Several of my sea-going friends seem to 

 regard them as flying fish, but naturalists well know that they are cephalopod 

 mollusks, and belong to a diS'ereut division of the animal kingdom to that 

 •which includes the fishes. Their flight is curious. I know no better term 

 than that vague and hackneyed one : the terms " sagitta," " sagittatus," 

 given not only to the present but to several other species, suflflciently 

 indicate the habit, although these terms have been supposed to have 

 reference to the feather or pen concealed, rather than to their arrow-like 

 flight. It is probably when pursued by the porpoise, the tunny, aibacore or 

 bonito that this flight takes place ; but some believe that the flight of fishes 

 (Exocetus) and squids (Loligo, Teuthis and Ommastrephes) is merely an act 

 indicative of exuberant spirits and animal enjoyment. I will not speculate 

 on this, but try to give some slight idea of a seeming anomalous mode of 

 locomotion. All the mollusks consist of a body, head, mouth, funnel and 

 foot ; in these larger and more highly organized, or, as some call them, 

 typical mollusks, this foot is divided into eight long and almost linear strips 

 furnished with sucking disks, which thus become prehensile organs: technical 

 naturalists call these divisions, legs, arms, fingei-s, tentacles, tentacular arms, 

 &c., with praiseworthy indiff'erence. When a rapid act of progression has to be 

 performed, the animal assumes what wc should consider a reversed position, 

 and drives itself backwards by the sudden and violent expulsion of water 

 through the funnel : the body then takes the lead ; and the divisions of the 

 foot collapse, and fold together much after the fashion of a closed umbrella : 

 if 3'ou can imagine an umbrella flashing through the water point foremost 

 with the velocity of hghtning, you obtain a very good idea of the locomotive 

 powers of these mollusks : they not only cleave the water in this arrow-like 

 flight, but, leaving the water, enter on the realms of air, continuing their 

 course in the same direction : their powers of flight are of course limited, 

 as the air furnishes them with no fulcrum for taking a second flight when 

 the impetus gained by the first is exhausted ; so they fall into the ocean, 

 and then regain their powers of flight; or, as occasionally happens, get 

 stranded on the deck of a ship, and there, after exciting much wonder 

 and some fear, perish miserably by the hands of the sailors. A friend of 

 mine who passes most of his nights on tropical seas, insists that these squids 

 are luminous, that, as they shoot through the water and produce the effect 



