40(i PROCEEDINGS OF THE ACADEMY OF [July, 



type 4 and identified with the Sepiola Japonica of d'Orbigny, although 

 upon exactly what grounds other than general probability does not 

 seem to be entirely clear. A great many points yet remain to be 

 cleared up, and, as I have been able through the kindness of Prof. 

 Yerrill himself to secure the use of the majority of his specimens, 

 they have been made the basis of the more extended description of 

 the species given herewith: 



Body short and saccular; mantle in the male somewhat ..bell- 

 shaped, widest in front, tapering rapidly to a rounded posterior 

 extremity; in the adult female more rounded and cylindrical, less 

 tapering, and relatively much more plump. Nuchal commissure 

 rather wide, but considerably narrower than in Euprymim morsei. 

 Mantle margin usually, but not ahvays, more or less emarginate 

 beneath, permitting the siphon a greater freedom of movement. 



Fins thin, small, subcircular, forming a lobe in front; attachment 

 narrow, considerably above the median horizontal plane of the 

 body; position with regard to the mantle almost median in the 

 adult, but in the young placed much further back. 



Head oblong, flattened above; width inclusive of the eyes about 

 twice the length. Funnel long, tapering, rather slender. Locking- 

 apparatus comprising an oblong groove on either side of the base 

 of the funnel and folds to correspond on the inner surface of the 

 mantle. The grooves are provided with a thickened reflexed margin. 

 The folds are simple narrow ridges, much longer than the grooves. 



Eyes of moderate size; openings small. "Olfactory organ" 

 situated considerably below and behind the lid opening. 



Arms short, fleshy, but fairly slender; the first pair the shortest 

 and smallest, the rest subequal; third pair obscurely carinate, 

 stouter and somewhat longer than the others. A poorly developed 

 web connects the arms at the base, but is obsolete or wanting between 

 the ventral pair. Suckers in two alternating rows; in the female 

 very minute and alike on all the arms; somewhat modified in the 

 male. Left dorsal arm of the male very conspicuously hectocotylized ; 

 at its extreme base appear one or two very minute and rudimentary 

 suckers, these immediately succeeded by a huge ridge-like swelling, 

 irregularly oval in shape and somewhat suggestive of the concha 

 of the human ear; this curious organ extends about half way up the 

 arm and is apparently formed by the fusion of exceedingly modified 

 obscured sucker pedicels, though it bears no suckers. The 

 he structure given by Ortmann is recognizable, but scarcely 



species, /. morsei, has since become the type of Steenstrup's genus . 

 Euprymna. 



