[199] CEPHALOPODS OF NORTHEASTERN COAST OF AMERICA. 409 



SUPPLEMENT. 



After the preceding pages were put in type, a number of additional 

 specimens were received, some of them of great interest. Among these 

 there are some forms that appear to have been previously unknown. 

 These are, therefore, described in this place. Moreover, several papers 

 have been published, on the same subject, during the printing of this 

 report. Some of these include certain of the species above described, 

 and, therefore, may well be noticed here. 



ARCHITEUTHIS Harting, 1861. (See pp. [25], [114].) 



Architeuthus Steenstrup, Forhandl. Skand. Naturf., 1856, vii, p. 182, 1867 (no descrip- 

 tion ) 



PlectoteuthU Owen, Descriptions <>f some new and rare Cephalopoda. Part II. 

 < Trans. Zool. Soc. London, xi, part 5, p. 156, pi. 34, 3">, June, 1881. 



Professor Owen, in the paper quoted, has given a somewhat detailed 

 description, with figures, of the large cephalopod arm, long preserved 

 in the British Museum. This arm had previously been pretty fully 

 described by Mr. Saville Kent, in 1874, whose description has already 

 been quoted by me. (See pp. [57-59].) Professor Owen, like Mr. Kent, 

 fails to state to which pair of arms the specimen belongs. This is a 

 very important omission, for in Arch i ten this, as in many other genera, the 

 arms belonging to different pairs differ in form and structure. The de- 

 scribers of this arm would, doubtless, have been able to ascertain to 

 which pair it belongs by a direct comparison with the arms of Ommas- 

 trephes, or any other related form. For this arm, Professor Owen en- 

 deavors to establish a new genus and species (Plectoteuthis grandis). 

 The genus is based mainly on the fact that there is a marginal crest 

 along each outer angle, and a narrow protective membrane along each 

 side of the sucker-bearing face. These peculiarities are precisely those 

 seen in the ventral arms of Architeuthis, and have already been described 

 by me in former articles, and in this report (see pp. [35], [37], [44]), both 

 as found in A. Harveyi and A. princeps. Similar membranes or crests 

 are found on the dorsal arms of Sthenoteuthis pteropus (see PL XVII, fig. 

 7 a), and other related species. 



The suckers on the arm, as described and figured by Professor Owen, 

 are like those of ArcMteuthis. Therefore there is no ground whatever 

 for referring this arm to any other genus, and Plectoteuthis must become 

 a synonym of ArcMteuthis. 



Whether the arm in question belongs to a species distinct from those 

 already named, I am unable to say. There is, apparently, nothing to 



