A. E. Verrill — North American Cephalopods. 197 



Special Descriptions of the Atlantic Coast Species. 

 Architeuthis Steenstrup. 

 Oplysninger om Atlanter, Collossale Blfcksprutter. Forhandlinger Skand. Naturf., 

 1856, vii, p. 182, Christiana, 1857. 



Size large. Body stout, nearly round, swollen in the middle. Caudal 

 tin, in the typical species, very small, sagittate (very large, broad, 

 rhomboidal in A. megap>tera).* Head large, short. Eyes very large, 

 oblong-ovate with well-developed lids and anterior sinus. Sessile arms 

 stout, their suckei'S large, very oblique, with the edges of the horny 

 rings strongly serrate, especially on the outer margin. The margin 

 has around it a free-edged membrane, which closely surrounds the 

 denticles when the sucker is used, and allows a vacuum to be produced. 

 Tentacular-arms very long and slender, in exteiision, the proximal 

 part of the club furnished with an irregular group of small, smooth- 

 rimmed suckers, intermingled with rounded tubercles on each arm, 

 the suckers on one arm corresponding with the tubercles of the other, 

 so that, by them, the two arms may be firmly attached together 

 without injury, and thus used in concert ; other similar suckers and 

 tubercles, doubtless for the same use, are distantly scattered along 

 the slender part of these arms, one sucker and one tubercle always 

 occurring near together. The internal shell (known only in one 

 species) is thin and very broad, expanding from the anterior to the 

 posterior end, with divergent ribs. 



This genus is closely allied to Ommastrephes^ from which it may be 

 best distinguished by the presence of the peculiar suckers and tuber- 

 cles for uniting the tentacular-arms together. A small cluster of 

 smooth-edged suckers also occurs at their tips. 



Architeuthis Harveyi Verriii. 



Megaloteuthis Harveyi Kent, Proc. Zool. Soc. London, 1874, p. 178. 



Architeuthis monachus Yerrill, Amer. Journal Science, vol. ix, pp. 121, 177, PI. ii, 



iii, iv, 1875; vol. xii, p. 236, 1876. American Naturalist, vol. ix, pp. 22, 78, 



figs. 1-6, 10, 1875, (? non Steenstrup). 

 Ommastrephes harveyi 'Kent, Proc. Zool. Soc. London, 1874, p. 492. 

 Ommasirephes (Architeuthis) monachus Tryon, Manual of Conchology, I, p. 184, PI. 



83, fig. 379, PI. 84, figs. 380-385, 1879. (Descriptions compiled and figures copied 



from the papers by A. E. T.) 



Plates XIII, XIV, XV, XVI, XVIa. 

 The diagnostic characters of this species, so far as determined, are 

 as follows: Sessile arms unequal in size, nearly equal in length, 



* This species differs so much in dentition and other characters from tlie typical 

 forms, as to deserve separation, as a subgenus, or perhaps as a distinct genus, which I 

 propose to call Sthenoteuthis. 



