30 U.S. NATIONAL MUSEUM BULLETIN 234 



ML 54.0-26.0 mm., Sta. D5442 off San Fernando Point, west coast 

 of Luzon, coral sand in 77 m.. May 10, 1909 (all but one are in poor 

 condition) ; USNM 575348. 



Description. — This species is represented in the collections by one 

 female with a mantle length of 91.0 mm. and by five specimens, in 

 rather poor condition, which are tentatively referred to this species. 



The mantle is roughly oval, dorsoventrally flattened and bluntly 

 pointed posteriorly. The anterior margin is produced dorsally as a 

 rounded triangular lobe and ventrally is nearly straight. 



The funnel is stout and long and projects slightly beyond the bases 

 of the ventral arms. The mantle locking apparatus is stout. No 

 funnel organ could be distinguished, but there is a triangular valve. 



The fins are long and narrow. They originate only 1 to 2 mm. 

 from the margin and have free lobes posteriorly. They are very 

 narrow. 



The head is large, stout, with large eyes and conspicuous lower 

 lids. The buccal membrane is seven-pointed and free of suckers. 

 No spermatophoric pad could be seen. 



The arms are in the order 4.3.2.1 or 4.3.1.2 and are short and stout. 

 There is a low interbrachial web, missing in E, low in A and B, and 

 deepest in C and D sectors. The arms are broad basally but with 

 narrow to slender tips. I and II are rounded aborally, but III is 

 slightly compressed with a low ventral keel and IV is strongly com- 

 pressed with a prominent keel extending along its entire length. The 

 suckers are quadriserial with a low protective membrane on each side. 

 The suckers are very finely serrated on then horny rings. 



The tentacles are long, slender, and slightly compressed, and bear 

 small curved clubs. There is a narrow web on the dorsal side originat- 

 ing below the most proximal sucker and extending almost to the tip. 

 The suckers are bounded on both sides by low protective membranes 

 which do not unite basally but continue along the stalk as two parallel 

 low ridges. The suckers are minute, about 0.3 mm. in diameter, and 

 uniform in size except for two enlarged suckers in the anterodorsal 

 corner of the club. The exact number of rows of suckers in the flaccid 

 club is difficult to determine, but probably more than 10 rows are 

 involved. The horny rings are finely toothed. 



The shell is broad, elliptical, with both ends about equal and slightly 

 pointed. Dorsally, the shell is convex posteriorly but nearly fiat an- 

 teriorly with a low median ridge and shallow parallel grooves. There 

 is a narrow chitinous border; the rest of the dorsal surface is calcified 

 and marked by somewhat pointed concentric lines of rugose papillae. 

 Ventrally, the shell is convex in the anterior half and strongly concave 

 in the posterior half. The outer cone is thin posteriorly, and flared 

 out and up. The striated area occupies a little more than half of the 



