238 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [28] 



vary greatly according to the state of contraction or relaxation. The 

 length given (24 feet) probably represents the extreme length in an ex- 

 tended or flaccid condition, snch as usually occurs in these animals soon 

 after death. The slender portion is nearly three-cornered or triquetral 

 in form, with the outer angle rounded, the sides slightly concave, the 

 lateral angles prominent, and the inner face a little convex and gener- 

 ally smooth (Plate I, fig. 1, e c.) 



The terminal portion, bearing the suckers, is 7G.2 cm in length and ex- 

 pands gradually to the middle, where it is 11.4 cm to 12.7 cm in circumfer- 

 ence (15.3 cm when fresh) and 3.9 cm to 4.1 cm across the face. The sucker- 

 bearing portion may be divided into three parts. The first region (* to i i) 

 occupies about 17.8 cm (7 inches); here the arm is rounded-triquetral, 

 with margined lateral angles, and gradually increases up to the maxi- 

 mum size, the inner face being convex and bearing about forty irregu- 

 larly scattered, small, flattened, saucer-shaped suckers, attached by very 

 short pedicels, and so placed in depressions as to rise but little above 

 the general surface. The larger ones are 5 mm to G"" n in external diameter; 

 3 ,nm across aperture; 1.5 mm high. The smaller ones have a diameter of 

 4" ,m ; aperture, 2.5 ram ; height, l mm . The homy ring (Plate IV, Figs. 9, 9a) 

 is circular, thin, and of about uniform breadth all around ; the edge is 

 smooth and even, slightly everted ; just below the edge there is a groove 

 all around ; below this a prominent, rounded ridge surrounds the pe- 

 riphery, below which the lower edge is somewhat contracted. A thick, 

 soft membrane surrounds the edge. These suckers are at first distantly 

 scattered, but become more crowded distally, forming six to eight irreg- 

 ular alternating rows, covering the whole width of the inner face, which 

 becomes 4.1 cm broad. Scattered among these suckers are about an equal 

 number of low, broad, couical, smooth, callous verrucas, or wart-like 

 prominences, rising above the general surface, their central elevation 

 corresponding in form and size to the apertures of the adjacent suckers. 

 These, without doubt, are intended to furnish secure points of adhesion 

 for the corresponding suckers of the opposite arm, so that, as in some 

 other genera, these two arms can be fastened together at this wrist-like 

 portion, and thus may be used unitedly. By this means they must 

 become far more efficient organs for capturing their prey than if used 

 separately. The absence of deuticulations prevents the laceration of 

 the creature's own flesh, which the sharp teeth of the other suckers 

 would produce under pressure, and the verrucas prevent the lateral 

 slipping, to which unarmed suckers applied to a smooth surface would 

 be liable. Between these smooth suckers and the rows of large ones 

 there is a cluster of about a dozen small suckers, with sharply serrate 

 margins, from o mm to 8 mm in diameter, attached by slender pedicels. They 

 are arranged somewhat irregularly in four rows, those of the outer 

 rows more oblique, and corresponding in form with the larger marginal 

 suckers. 



The second division (ii to iii), 35.G" 11 in length, succeeds the small suck- 



