[133] CEPHALOPODS OF KORTHEASTERN COAST OF AMERICA. 343 



Lcligo Pealei Lesueur — (Continued). 

 Variety pallida Verrill. 



Loligo pallida Verrill, Rep. Invert. Viney. Sd., in Rep. U. S. Com. Fish and 

 Fisheries, vol. i, p. 635 [341], pi. 20, figs. 101, 101 a, 1874. 

 Tryon, Man. Conch., p. 143, pi. 52, figs. 141, 142 (descr. and figs, copied from 



preceding). 

 Verrill, Amer. Journ. Sci., vol. xix, p. 292, 1880. 

 Loligo Pealei var. pallida Verrill, Trans. Conn. Acad., vol. v, p. 317, pi. 28, figs. 

 1-6, 1831. 

 Plate XXVI, figures 1-4. Plate XXVII, figures 1-4 (pens). Plate XXVIII, figures 1-9, 

 Plate XXIX (anatomy^). Plate XXX (young). Plate XXXI, figures 1-3. Plate 

 XXXII, figure 2 (anatomy 9 ). 



Body rather elongated, more or less stout, according to state of disten- 

 tion or contraction,* tapering backward to a moderately acute posterior 

 end, more acute in the male than in the female. Caudal fin long-rhom- 

 boidal, with the outer angles very obtusely rounded, and varying, 

 according to age, in the ratio of its length to its breadth, and greatly, 

 also, in the proportion that its length bears to that of the mantle.t The 

 length of the caudal fin, in proportion to that of the body (mantle), 

 although variable, normally increases with age, even after sexual matur- 

 ity. In this species, with specimens having the mantle from 100 mm to 

 125 mm long, the ratio of the fin to the mantle usually varies from 1 : 1.80 

 to 1 : 1.90 ; with the mantle 150 mm to 175 mm long, the ratio usually becomes 

 1: 1.G5 to 1:1.75; in the largest specimens, with the mantle 2G0 mm to 

 400 mm long, the ratio varies from 1 : 1.50 to 1 : 1.G5, rarely becoming 

 1 : 1.75. The ratio of the breadth of the caudal fin to the length of the 

 mantle, in the larger male specimens, ranges from 1 : 2.12 to 1 : 2.40, 

 varying considerably according to the mode of preservation; in the 

 larger females it varies from 1 : 1.70 to 1 : 2.12. 



The anterior ventral edge of the mantle recedes, in front of the siphon, 

 in a broad curve, leaving an obtuse angle at either side, opposite the 

 lateral cartilages; from these angles it again recedes, on the sides, in a 

 concave line, and then projects considerably forward, forming a promi- 

 nent median dorsal lobe, which gradually tapers from the base, and 



* The mantle, when the gill-cavity is distended with water, has a larger size than 

 when the water is expelled by the contraction of its walls, which is usually the con- 

 dition in which specimens die. Moreover, when the large stomach is distended with 

 food, and when the ovary is distended, in the breeding season, with eggs, the form is 

 stouter than usual. 



tThis variation is largely independent of sex, and is due partly to the ordinary 

 changes during growth, partly to the condition of the muscular tissues at the time of 

 death, and partly to the effects of the alcohol in which they have been preserved. 

 These latter causes, in the case of preserved specimens,moro or less obscure the effects 

 of growth in causing the proportions to change. 



The most marked effect of strong alcohol is to reduce the diameter of the body and 

 the breadth of the caudal fin to a proportionally far greater extent than it does the 

 length of the mantle and fin. Therefore, with specimens that have been preserved 

 in too strong alcohol, the females resemble the males in form, and the males often look 

 like a different species, on account of their unnaturally long and narrow fins and very 

 slender bodies. 



