1889.] ANATOMY OP GONATTJS FABRICII. 133 



From this table we may extract the following sets of resemblances 

 and differences : — 



A. Gonatus resembles both Onychoteuthis and Enoploteuthis in : — 

 (2) the fact that the club of the tentacle has both liooks and 



suckers, though it differs widely in their arrangement ; 



(5) the fact that the funnel has a valve and a funnel-organ ; 



(6) the simple siphono-pallial articulation ; 



(16) the number (though not the disposition) of the oviducts. 



B. Gonatus resembles Onychoteuthis and differs from Enoplo- 

 teuthis in ; — 



(4) the extension of the fins beyond the end of the body proper ; 

 though even here a difference in their relation obtains owing 

 to the varying form of the pen, which, however, has aphrag- 

 mocone in both ; 



(9) the fusion of the middle portions of the median retractors of 



the head ; 



(11) the absence of the nuchal muscle ; 



(12) the form of the median tooth of the radula ; 

 (18) the presence of nidamental glands. 



C. Gonatus i-esembles Enoploteuthis and differs from Onycho- 

 teuthis in : — 



(10) the separation between the median and lateral retractors of 

 the head ; 



(13) the rudimentary anterior salivary glands; 



(14) the symmetrical anal appendages ; 



(17) the situation of the oviducts dorsal to the roots of the gills. 



D. Gonatus differs from both Onychoteuthis and Enoploteuthis 

 in : — 



(1) the arrangement of suckers in 4 rows and in their armature; 

 ('2) the details of armature of the tentacular club ; 



(3) the connective apparatus of tlie tentacles ; 



(4) the exact relation of the end of the body to the fins; 



(7) the presence of a siphonal cartilage ; 



(8) the form of the pen ; 

 (12) the radula; 



(15) the absence of accessory hearts. 



In regard to A the most noticeable fact is that no points of 

 importance have been elucidated in which Gonatus resembles both 

 the other forms under consideration except such as are also common 

 to a much larger number of forms. 



The characters grouped under D are, I think, sufficient to justify 

 the step taken three years ago in making this genus the type of a 

 new subfamily Gonatidce, for there can be no doubt that it is incom- 

 parably further removed from Onychoteuthis and Enoploteuthis than 

 they are from each other. 



The question which of these two genera it more nearly resembles 

 is more difficult to settle ; but I should be disposed on the whole to 

 attribute more weight to the characters which ally it to Onychoteu- 



Proc. Zool. Soc— 1889, No. X. 10 



