78 U.S. NATIONAL MUSEUM BULLETIN 2 34 



USNM 575170. 6 99, ML 55.0-175.0 mm., 9 cf cf, ML 73.0-97.0 

 mm., Surigao, east coast of Mindanao, 150-foot seine, May 8, 1908; 

 USNM 575166. 40 juv., ML 26.0-41.0 mm., 3 cfcf, ML 56.0-68.0 

 mm., 20 99, ML 43.0-148.0 mm., Mansalay, southeastern Mindanao, 

 150-foot seine, June 4, 1908; USNM 575167. 4 d'd", ML 82.0- 

 99.0 mm., 10 99, ML 64.0-107.0 mm., Hinunangan Bay Beach, 

 Leyte, July 30, 1909; seine; USNM 575169. 



Description. — This species is perhaps the most distinctive of all 

 the Phihppine cephalopods and is known from Austraha to Japan 

 and the Hawaiian Islands. 



The mantle is long and tubular, bluntly rounded posteriorly. 

 Anteriorly the margin is produced on the dorsal midline and slightly 

 excavated beneath the funnel with sharp lappets on either side. 



The fins are large, extending from 1 to 2 mm. from the anterior 

 lateral margin of the mantle to the posterior end. The fins are united 

 posteriorly around the end of the mantle by a fleshy ridge. Together 

 they form a broad oval outhne, which is broadest about one-third of 

 the length of the mantle from the posterior end. 



The funnel is long and set deeply into the ventral surface of the head. 

 The funnel locking apparatus is strong, straight, and firmjy connected 

 by a deep groove on the funnel and a straight ridge on the mantle. 

 The funnel valve is exceptionally well developed and prominent. 



The head is broad and stout, wider than the mantle, with prominent 

 eyes. There is a small olfactory crest below and ventral to the eyes. 



The arms are in the order 3.4.2.1, I being much smaller and more 

 slender than the rest. All the arms are somewhat flattened and 

 keeled for at least part of their length. Arms I are small, slender, 

 flattened v/ith slender tips, equipped with a keel for the distal half 

 or two-thirds. Arms II are slightly squarish in cross-section with a 

 low keel on the ventral border extending from the base to the tip of 

 the arm. Ai'ms III are strongly flattened and equipped with a keel 

 or swimming membrane extending the entire length. This keel is 

 deepest at the midpoint of the arm. Arm IV is subequal in length 

 to III, the dorsal edge thin and with a web connecting with III at 

 the base for the protection of the tentacle. The ventral edge is also 

 keeled for the entire length. 



The sessile suckers are bordered on either side on all arms by pro- 

 tective membranes with stout supports, the membrane being largest 

 and deepest on III where the dorsal membrane is much wider than 

 the ventral one. The suckers are closely set, round, with stout 

 peduncles. The horny ring of the suckers of the midportion of III 

 bears 18 to 20 sharp, pointed triangular teeth. 



In the male the left ventral arm is hectocotylized by a modification 

 of the distal third of the arm. BasaUy there are about 23 normal 



