589 



length of 240 mm. we have 46 suckers or the transverse bars of the mem- 

 brane on the inner row and the same number of peduncles of the suckers 

 on the outer. In this specimen the suckers are present up to the 27th 

 on the inner, and 26 th on the outer row; the peduncles of the suckers 

 on the inner row are seen up to the 23 rd where it is represented by a 

 small knob, whereas the transverse bars of the outer row are seen only 

 up to the 13 th. 



In a specimen from Miye, the mantle length of which measures 

 230 mm., we find 50 transverse rows on the inner side, of which the 

 proximal 36 are suckered, the following three are not, while the 40th, 

 the 42 nd, the 43 rd, and the 44 th are again suckered. Thus there are 

 more suckers present in this specimen than in the others above mentioned. 



But in a still smaller specimen than the last, i. e. in a sj)ecimen 

 from Uodu, Japan Sea, with the mantle length of 240 mm. we count 46 

 transverse bars on the inner row and the same number of peduncles of 

 the suckers on the outer. In the inner row of this specimen the proxi- 

 mal 22 are suckered, while in the outer, 16 are with suckers. The 

 stalks of the suckers on the inner row are seen to the 31st whence they 

 disappear, while the last trace of the bars of the outer row is seen only 

 up to the 18 th. 



In a small specimen with the mantle length of 160 mm., (O 2) (Fig. 4), 

 from Iwami, Japan Sea, 49 pairs of suckers are counted from the 

 base of the arm to the very small ones at the tip. The flattening of the 

 distal portion of the arm, as well as the development of the membrane 

 on the outer side are similar to those of the larger specimens, but both 

 the pairs of the suckers are present as far as the extreme end, those of the 

 outer becoming smaller from about the 17 th distally. The transverse 

 bars are prominent on the inner row, but become lost on the outer in 

 the distal portion from about the 26 th. 



From this it will be seen that the hectocotylization of the Pacific 

 form of 0. sloanei [0. sloa nei paci ficus), differs greatly from the Atlan- 

 tic representative, but is very like that of the southern form, the de- 

 scription of which as given by Pfeffer being applicable, Avith almost no 

 alterations, to the small specimen above given, the male examined by 

 the German author being nearly of the same size as our Iwami specimen 

 (the Goettingen male of sloanei sloanei described by Pfeffer is stated 

 to measure 170 mm. mantle length, whereas our specimen measures, as 

 above given, 160 mm ). But the suckers as well as the peduncles on the 

 inner row, in the northern form, are, as above stated, subject to great 

 variations, becoming liable to be lost as the animals grow larger. 

 Whether this is the case with the southern form, i. e. vfith sloanei sloanei, 

 is to be left for future investigations. 



