40 U.S. NATIONAL MUSEUM BULLETIN 234 



Key to the Species of Sepiadarium 



1. Fins narrow; nearly four-fifths (FLI 78.0) as long as mantle; mantle width 



greater than the length (MWI 111.2); arm formula 3.1 = 4.2; mantle and 

 head covered dorsally by small round patches of pale red or brown and 



fine black or dark brown spots S. auritum Robson, 1914. 



Fins narrow; about one-half mantle length; mantle width variable; arm 

 formula not as above; no pigment present 2 



2. Mantle width about one-half mantle length (MWI 59.3); fins less than half 



mantle length; arm suckers in two rows; tentacular club suckers in six 

 distinct rows; tentacular stalk as thick as arms and shorter than III; arm 



formula 3.1.2.4 S. gracilis Voss, 1962 



Mantle width much more than half mantle length, nearly equal to latter; fins 

 about half mantle length; arm suckers partly in four rows; tentacular club 

 suckers in six to eight rows; arm formula variable 3 



3. Mantle width greater than length (MWI 101.5); fins less than half mantle 



length; arm suckers in four rows on at least part of arm; hectocotylized 

 arm of male armed with series of conical lamellae on distal portion, not 

 bounded by distinct folds or continuous membranes. 



S. austrinum Berry, 1921 



Mantle width less than length; fins less than half length of mantle; arm 



suckers in four rows on at least part of arm; hectocotylized arm of male 



armed distally with a series of grooved transverse padlike lamellae bounded 



on the ventral side by a wide fleshy crenulated vertical membrane ... 4 



4. Arm formula usually 3.1 = 2.4 or 3.1.2 = 4; females with a distinct space free 



of suckers down middle of median portion of arm; hectocotylized portion 

 of arm formed of about 18-20 low transverse ridges, bounded on the 

 ventral side by a wide fleshy crenulated vertical membrane. 



S. kochii Steenstrup, 1881 



Arm formula usually 3.2.1.4; females with only an incipient opening between 



the suckers; transverse ridges on hectocotylized arm of male more conical, 



more papillose, more elevated, and more numerous, with about 24 transverse 



ridges S. nipponianum Berry, 1932 



Berry (1932) gave a resume of the differences between nipponianum 

 and kochii and considered them of sufficient value to constitute specific 

 differences, but the differences are of a minor nature (mostly in degree) 

 and apparently are not constant; nipponianum may eventually be 

 found to be only a subspecies of kochii. 



Family Sepiolidae: Subfamily Rossiinae 



Rossia bipapillata Sasaki, 1920 



Figure 4, c-e 



Rossia bipapillata Sasaki, 1920, p. 190, pi. 25, fig. 3; 1929, p. 160, pi. 16, figs. 18, 19; 

 text figs. 98-99. 



Material.— 1 9, ML 39.0 mm., Sta. D5412, off Lauis Point, be- 

 tween Cebu and Bohol in 113 m., temp. 54.8° F, Mar. 23, 1909. 



