2 7 8 



BULLETIN OF THE BUREAU OF FISHERIES. 



Head small and very indistinctly delimited because so deeply embraced in the mantle. Eyes 

 large, spherical, protruding, a distinct constriction separating them from the head at the base. Fun- 

 nel of robust proportions, but thin-walled and extremely long, reaching nearly midway of the ventral 



arms; broad at the base, but thence rapidly ta- 

 pering to the simple circular aperture at the 

 apex. Funnel organ prominent, of a whitish 

 color; it comprises a large A -shaped cushion on 

 the dorsal wall a little anterior of the middle, 

 and a somewhat shorter and narrower elongate- 

 ovate organ on either side of the ventral wall 

 just below it (fig. 5). Locking apparatus well 

 developed; just behind and a little below the 

 eye, the basal margin of the funnel on either side 

 is furnished with a small cartilaginous pit-like 

 depression, which articulates with a posteriorly 

 directed, roughly hook-like nodule on the inner 

 surface of the mantle; just outside this nodule 

 and passing below it parallel to the mantle mar- 

 gin, a shallow, though distinct, groove coincides 

 with a similar sulcus on the outer surface of the 

 mantle, so that the constriction thus formed 

 renders very prominent the thickened band of 

 transverse muscle bordering the mantle opening. 

 Armsof moderate length, perhaps half again 

 as long as body, sharply separated from body 

 at base by a deep sulcus; order of length 1,2, 3, 

 4; dorsal arms somewhat the thickest and strong- 

 est as well as the longest, their distal portions 

 furnished with the usual conspicuous wing-like 

 expansions of the marginal membrane, much 

 wrinkled and contracted in preserved speci- 



FiG. 3. — Argonaula boltgeri, lateral view of female [165], X 2. 

 Drawn by R. L. Hudson. The drawing does not show the 

 characteristic flexures of the body. 



mens so that its exact outline is very difficult of 

 determination ; remaining arms broad at the base, but 

 rapidly tapering to an attenuate extremity. Urn- 

 brellarudimentary , comprising only a short fold inter- 

 webbing all the arms for a distance of about three 

 millimeters from their base. Suckers very large, 

 much elevated, 40 to 50 or more in number on each 

 arm (on the dorsal arms over 50 suckers in each row, FlG . 

 on thesecond and third arms about3o in each row, and 

 on the ventral arms about 18 to 20 in each row) ; com- 

 pactly and very regularly ranked in two alternating rows, which on the second arm (and to a very slight 

 degreeon the others as well) become ultra-marginal and very widely separated distally (pi. XLViii.fig. 5); 

 cups flattened and discoid; both rows persistent tothetipsof all the arms, though vastly reduced on the 



Argonaula boUgeri, lateral view of shell of female 

 [165], X 2. Drawn by R. 1/ Hudson. 



