188 THE VOYAGE OF H.M.S. CHALLENGER. 



Arms short compared with the body, furnished with two rows of globular 

 suckers. 



Tentacles present, and bearing four rows of suckers on the distal extremity (Tctonius 

 pavo, doubtful as regards the last point, owing to mutilation). 



Gladius long and narrow, somewhat expanded towards the fins and forming a hollow 

 pointed cone behind. 



The genus Taonius was established by Steenstrup in 1861 to mdnde LoUgo jxtvo, 

 Lesueur, and Taonius liyperhoreus, and since his description has been overlooked by most 

 subsequent writers it may not be out of place to translate some parts of it. 



In the first place, the whole family Cranchiseformes is characterised thus : " The 

 mantle is firmly united with the head at three separate points — namely, directly in the 

 dorsal median line, and indirectly by means of the funnel on either side of it, where there 

 is usually a movable sliding cartilaginous articulation or hook in other Cephalopoda."^ 

 Then, under the heading Taonius hyperboreus, he adds : "As soon as the relations of 

 the tentacles and the structure of the arms in the genus Leacliia, are carefully considered, 

 it is obvious that Loligopsis pavo, Lesueur, and Leacliia hyperhorea, Steenstrup, which 

 have hitherto been referred to it, must form a separate group. For in addition to the 

 fact that the latter species has, and the former seems to have had, tentacles, both have 

 narrow elongated fins, which extend along a large portion of the body, and are strikingly 

 characterised by their enormous eyes, which almost meet on the ventral surface, and by 

 a funnel, which is shorter and smaller than that of Leachia. The gladius agrees very 

 well with that of other Cranchias, but may, on the whole, be described as expanded at 

 the inferior extremity." 



" The generic name Taonius is chosen more especially with reference to the longest 

 known species, whose beautiful coloured spots suggested the specific name j9«i'o ; how far 

 similar spots may have been present on the body of my species hyperboreus, I cannot 

 say. ... In case a division of the genus should become desirable, I regard the older 

 species Lol. pavo, Les., as the type." 



It appears from these passages that Steenstrup regarded Loligo pavo, Lesueur, as the 

 type of his genus, and he did not consider it essential to make a long and detailed state- 

 ment of its characters, because d'Orbigny had already done this when in 1839 he took 

 Lesueur's Loligo pavo, named it Loligopsis p)avo, and then proceeded to draw up a full 

 generic diagnosis based upon this specimen and upon another {Taonius cymoctypus) 

 which he erroneously regarded as belonging to the same species ; in other words, Steen- 

 strup's Taonius is practically identical with d'Orbigny's Loligopsis. It is of great 

 importance that this should be clearly understood, because in 1882 Professor A. E. Verrill 

 constituted* a ncAV genus, Desmoteuthis, based upon a specimen captured near the 



1 OverWLk, p. 70. ^ Cipli. N. E. Amer., p. 216. 



