32 U.S. NATIONAL MUSEUM BULLETIN 291 



The funnel is long and narrow; it extends nearly to the level of 

 the posterior edge of the eye opening (pis. 1b; 2a). Between the 

 components of the locking apparatus the posteroventral margin of 

 the funnel is broadly U-shaped and is weakly muscled. The tube of 

 the funnel is long and narrow; the opening is small. The collar of 

 the funnel is thin-walled and weakly developed; it does not form a 

 strong anterior fold. The funnel retractor muscles are strong and 

 robust. They extend posteriorly from the dorsal w^all of the funnel 

 and the bases of the locking-apparatus components to the posterior 

 end of the mantle where they flare and insert along the shell-sac 

 and the mantle wall. The bridles of the funnel are broad, thin, weak 

 bands deeply embedded in the posterior depression of the funnel 

 groove. Integument and subcutaneous gelatinous connective tissue 

 blend the funnel smoothly with the surface of the head around the 

 collar and along the lateral borders of the funnel tube. The anterior 

 end of the funnel, however, lies free in the funnel groove. A small 

 pore lies in the midline of the funnel groove; a tube leads dorsally 

 from the pore, through the gelatinous tissue, and between the bridles. 

 I am conducting a separate study of this previously unreported struc- 

 ture which occurs in several oegopsid families. 



The cartilaginous components of the funnel-making locking ap- 

 paratus belong to the simple type. The funnel component is a long, 

 narrow structure with a smooth median sulcus that is deep and 

 narrow anteriorly but shallow^ and flaring posteriorly (pi. 2a, e). The 

 funnel component is bordered anteriorly and laterally by a thin, mem- 

 branous lip that fuses posteriorly with the thin, posteroventral 

 edge of the funnel. The mantle component of the locking apparatus 

 is a simple straight ridge that is most pronounced and distinct in 

 its anterior half; it diminishes and broadens posteriorly until it is 

 flush wath the inner w^all of the mantle (pi. 2a, d). 



The dorsal member of the funnel organ is a broad, inverted, 

 Y-shaped glandular structure (pi. 2f). The diagonal limbs are long, 

 slender, unsculptured, and rounded posteriorly. The median (anterior) 

 limb is short and blunt; it terminates with an erect, spatulate spire 

 that protrudes from the dorsal wall into the chamber of the exhalant 

 tube. 



The ventral members of the funnel organ are elongate, rounded 

 pads (pi. 2f). The median border of each is nearly straight and the 

 lateral border is broadly curved. The anterior and posterior ends are 

 rounded. 



The funnel valve is a large semicircular flap that extends across 

 the dorsal surface of the funnel tube just posterior to the opening 

 of the funnel (pi. 2f). A deep pocket is formed by the fusion of the 



