24 U.S. NATIONAL MUSEUM BULLETIN 234 



Distribution. — East Africa; Red Sea; India; Malay Straits; 

 Dutch East Indies; northern Australia; Philippines; Formosa; 

 southern Japan. 



Sepia prionota Voss, 1962 



Figure l,a-e; Plate 1,/,^ 



Sepia prionota Voss, 1962, p. 169. 



HoLGTYPE.— 1 9, ML 61.0 mm., Sta. D5151, from off Su'un Id., 

 Sulu Archipelago, Tawi Tawi group, in 44 m., coral sand and shell, 

 Feb. 18, 1908; USNM 575326. 



Paratypes.— 3 99, ML 26.0-36.2 mm., from Sta. D5151, from off 

 Sirun Id., Sulu Archipelago, Tawi Tawi group, in 44 m., coral sand 

 and shell, Feb. 18, 1908; USNM 575327. 



Other Material. — 1 9, ML 45.0 mm., from Sta. 5165, off Observa- 

 tion Id., Sulu Archipelago, Tawi Tawi group, 16.5 m., coral, Feb. 24, 

 1908. 



Diagnosis. — Keels of arms I-III equipped with widely spaced, 

 rounded erect lappets; arm and tentacular sucker rings armed with 

 long slender truncate teeth; numerous papillae on body, arms, and 

 head below eyes; sheU concave throughout. 



Description. — The mantle is rather slender, about half as wide as 

 long. Dorsally there is a broad rounded lobe in the midline, the 

 anterior mantle margin somewhat emarginate on each side. VentraUy 

 the mantle margin is straight, with a shallow squarish emargination 

 beneath the funnel without bordering lappets. Posteriorly the mantle 

 ends in a distinct fleshy point. 



The fins are long and narrow, originating 1 to 2 mm. posterior to the 

 margin but with distinct anterior lobes projecting slightly beyond the 

 margm and posteriorly separated with free lobes. The fins are 

 widest in the posterior third and are ruffled. 



The funnel is short and stout, with short but strong locking carti- 

 lages. The funnel projects nearly to the interbrachial area of IV. 

 The funnel organ could not be distinguished. There is a triangular 

 valve. 



The head is large, broad, slightly flattened; it bears large eyes with 

 strong ventral lids. The ventral surface is only slightly excavated 

 for the funnel. The buccal membrane has seven points with no 

 suckers. 



The arms are in the order 4.1=2=3, with IV 34-40 percent of the 

 mantle length; all are strongly compressed, rather thick at the base 

 and tapering to sharp points, not attenuate; aU are keeled on the 

 aboral sm'face but in a manner quite different from that observed in 

 other species. The keels on arms I-III are formed of a single series 

 of distinct, erect semicircular or elongate lappets, thick and fleshy, 



