312 



BULLETIN OF THE BUREAU OF FISHERIES. 



Euprymna scolopes Berry 1913. (PI. xxix, fig. 5-8, text fig. 23-26.) 



Euprymna nwrset Berry 1909, p. 418 (locality record only), not of Verrill. 

 Euprymna scolopes Berry 1913, p. 564. 



Animal small, sepioliform. Body short, thick, rounded; the transverse diameter usually equal to 

 about two-thirds to four-fifths of the length, but the entire outline and proportions very variable. Fins 

 large, semicircular; attached with a considerable degree of obliquity a little in advance of the middle of 



the body; broadest posteriorly ; anterior lobe conspicuous 

 and abruptly notched at its inward margin, so that the fin is 

 actually attached along only about the posterior two-thirds 

 of its length. Mantle united with the head in the nuchal 

 region by a broad commissure, so that the pallial aperture 

 extends but a very small distance past the eyeball, which 

 it partially encompasses posteriorly. Ventrally the man- 

 tle margin is sinuous and somewhat produced forward on 

 either side of the funnel, though with a more or less con- 

 spicuous emargination just beneath the latter. 



Head somewhat broader than long, its transverse 

 diameter usually a little less than that of the mantle, 

 but sometimes slightly exceeding it; broadly flattened 

 above, somewhat hollowed out below for the accommo- 

 dation of the funnel. Eyes somewhat swollen, large and 

 prominent. Funnel elongate conical; the extremity 

 nearly cylindrical, with thick walls, and a small apical 

 aperture; tip nearly or quite attaining the base of the 

 ventral arms; interior walls of tip minutely striate longi- 

 tudinally; the minute spoon-shaped valve is situated on 

 the dorsal wall just back of the striated area and is suc- 

 ceeded posteriorly by a region of strong transverse 

 striation. Funnel organ posterior in position and very 

 similar to that of E. morsei 

 (see Berry 1912b, p. 409). 



Arms rather short, stout; 

 usually as long as or a little 

 longer than the mantle; un- 

 equal, the brachial formula 

 consistently 2,3,4,1, although 

 the dorsal arms are only a 

 little shorter than the ventral ; 

 outer surfaces of ventral arms rounded, the others all furnished with a 

 delicate colorless carina or fold of membrane, best developed on the third 

 arms, but sometimes obscure even there. Umbrella rudimentary or lacking 

 (in some specimens) between the dorsal arms as well as those of the ventral 

 pair, better developed between the dorsal and second arms and between 

 these and the third pair; between each third arm and its ventral com- 

 panion it forms the usual broad sheath inclosing the base of the tentacle. 

 Suckers on all the arms in two rows at the extreme base, but the succeeding 

 pairs soon undergo an alternate lateral displacement, resulting in a four-rowed condition, which prevails 

 practically to the extremities of the arms; pedicels stout, conical; cups spherical, with small apertures, 

 and easily lost through abrasion; horny rings of larger suckers (at least in the female) smooth. 



In the female the suckers of the various arms are relatively minute and of subequal size at homologus 

 regions of the arms, but in the male a number of important modifications occur. In specimens of the 

 latter sex the left dorsal arm is conspicuously hectocotylized; the first four pairs of suckers at the base 



FlG. 23. — Euprymna scolopes, ventral view of male 

 [320] type, X i x A. Drawn by R. L. Hudson. 



Fig. 24. — Euprymna scolopes, 

 dorsal view of head of male 

 [320I, X iK Drawn by R. L. 

 Hudson. 



