86 U.S. NATIONAL MUSEUM BULLETIN 291 



The tentacles of Ctenopteryx are long and slender. The tentacular 

 stalks are naked. In proportion to the length of the tentacle, the clubs 

 are short and unexpanded; they bear no distinct carpus, manus, or 

 dactylus. Eight to fourteen rows of minute, closely packed suckers 

 cover the oral surface of the club. A thin, narrow keel extends along 

 the dorsel aboral border of the club. Protective membranes are lack- 

 ing. The clubs of Ctenopteryx and Bathyteuthis are similar in basic 

 design, but Ctenopteryx tends to have a few (up to four) more rows 

 of suckers. 



The connectives from the buccal membrane of Ctenopteryx attach 

 to the dorsal oral edges of arms I and II and to the ventral oral edges 

 of arms III and IV. This arrangement is in contrast to the dorsal, 

 dorsal, ventral, dorsal arrangement in Bathyteuthis. 



Ctenopteryx has 12-15 suckers in two rows on each of the buccal 

 lapi^ets. These are considerably more numerous and are slightly larg- 

 er than the burcal suckers of Bathyteuthis. 



The fins of Ctenopteryx are subterminal, and in adults they are near- 

 ly as long as the mantle. The fins consist, of long, muscular supports 

 connected by a thin web. In Bathyteuthis., too, the fins are subterminal, 

 but they remain small and simple throughout life. 



The suckers on the arms of Ctenopteryx originate at the bases of the 

 arms in 1 or 2 rows. In arm pairs I-III the suckers increase to six rows 

 on the distal half; arms IV retain two rows throughout. Bathyteuthis 

 has a similar increase to four rows. The suckers on the arms are minute 

 in both genera. Swimming keels and protective membranes are rudi- 

 mentary in both genera. 



Dentition on the sucker rings is usually a specific character; in 

 Ctenopteryx^ however, the sucker rings may be distinct at the generic 

 level, since they lack true teeth entirely. They bear only roughly scal- 

 loped borders. Bathyteuthis has sucker rings that bear truncate to 

 rounded teeth. 



The funnel organ in Ctenopteryx is very large. The dorsal member 

 has an inverted U- or V-shape with long, broad limbs. A distinct papilla 

 protrudes anteriorly from the apex. In Bathyteuthis the dorsal mem- 

 ber of the funnel organ is noticeably smaller, but since a great deal of 

 intraspecific variation exists in the structure of the funnel organ, no 

 strong significance can be placed on this difference alone. 



The gladius of Ctenopteryx has a long, narrow rhachis that is deeply 

 V-shaped in cross section. The narrow sides of the rhachis are straight, 

 and the lateral edges are tapered, not rolled under. A heavy, median 

 ridge extends the length of the gladius; the ridge tapers posteriorly 

 along the vane and terminates just before the end of the gladius. The 

 vane is thin, broad, and rounded. A conus is lacking, but the postero- 



