284 A. E. Verrill — ISforth American Cephalopods. 



Their habit of discharging an inky fluid through the siphon, when 

 irritated or alarmed, is well known. The ink is said to have caustic 

 and irritating properties. 



This squid, like the LoUgo, is eagerly pursued by the cod and 

 many other voracious fishes, even when adult. Among its enemies 

 while young, are the full grown mackerel, who thus retaliate for the 

 massacre of their own young by the squids. The specimens observed 

 catching young mackerel were mostly eight to ten inches long, and 

 some of them were still larger. 



From the rapidity with which the squids devour the fish that they 

 capture, it is evident that the jaws are the principal organs used, and 

 that the odontophore plays only a subordinate part in feeding. This 

 is confirmed by the condition of the food ordinarily found in the 

 stomach, for both the fishes and the shrimp are usually in fragments 

 and shreds of some size, and smaller creatures, like amphipods, are 

 often found entire, or nearly so ; even the vertebrse and other bones 

 of herring are often present. On the other hand, in some specimens, 

 the contents of the stomach are finely divided, as if the odontophore 

 had been used for that purpose. 



JVbtes on the Visceral Anatomy. 

 Plate XXXVIII, figure 2. Plate XXXIX, figijbe 2. 



This species, in common with others of the same genus, is very 

 different from Loligo Pealei in the form and structure of many of its 

 internal organs. The branchial cavity is larger and the gills (^, ^) 

 originate farther back and are much larger than in Loligo, their 

 length being about two-fifths the entire length of the body ; they 

 originate back nearly at the middle of the body. The liver (^, /) is 

 much larger and more conspicuous, consisting of two large, oblong, 

 lateral lobes or masses, closely united together in the median plane, 

 with a groove along the dorsal side, in which lies the oesophagus. ■ The 

 ink-bag (^) is elongated-pyriform, with a silvery luster externally, 

 but blackish when filled with the ' ink.' The size and form of the 

 stomach and its coecal lobe (s, s') vary greatly according to their 

 degree of distention with food. When well filled they are large, 

 thin, saccular, and more or less pyrifonn; the coecal lobe extending 

 back nearly to the end of the body. The intestine (/t) has two 

 spatulate papillae, one on each side of the anal orifice. 



The heart {H) is large, somewhat irregular, and unsymmetrical, 

 with four points, the two lateral continuous with the afferent vessels 



