284 
A. E. Verrill — North 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 Loligo , 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 iji fragments 
and shreds of some size, and smaller creatures, like amphipods, are 
often found entire, or nearly so ; even the vertebrae 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. 
Notes on the Visceral Anatomy. 
Plate XXXYIII, figure 2. Plate XXXIX, figure 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 (g,g) 
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 ( l , l) 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 (i) 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 pyriform; the coecal lobe extending 
back nearly to the end of the body. The intestine (A) 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 
