466 PROCEEDINGS OF THE NATIONAL, MUSEUM 



VOL. 89 



and forward as diverging scattered eyes to a level about as far an- 

 terior to the tentacles as behind them; cerebral eyes therefore not 

 merging into marginal eyes but separated from them by a 

 considerable space practically free from eyes (fig. 27). 



Color. — Cream to brown covered with small red or pink spots. 



Digestive tract. — Pharynx central, large, with large complex lateral 

 folds; mouth below anterior part of pharynx; intestine much 

 branched to periphery, not anastomosed. 



Reproductwe system. — Sexual apparatus removed from the two 

 largest specimens and sectioned but proved to be very immature 

 despite presence of genital pores ; it then became necessary to remove 

 the sexual region of the "type" specimen for sectioning; this was 

 mature but imperfect in the region of the penis papilla. Copulatoiy 

 apparatus typical of the genus Stylochus (fig. 28, a). Ends of vasa 

 deferentia with thick muscular walls forming accessory seminal vesi- 

 cles; these open into true seminal vesicle, forming tripartite organ; 

 muscular wall chiefly of circular muscles. Seminal vesicle tapers into 

 sinuous duct, which joins duct of prostatic vesicle. Prostatic vesicle 

 of moderate size, pyriform, with moderately thick wall of longitu- 

 dinal fibers pierced by ducts of prostatic glands; interior chambered. 

 Prostatic duct joins duct from seminal vesicle at base of penis papilla. 

 Penis papilla imperfect in available sections but appears to be of 

 elongate conical form (fig. 28, a) . Female pore short distance behind 

 male pore, leads into simple vagina only slightly muscular. Vagina 

 extends vertically, then curves downw\ard terminating by receiving 

 the uteri. Numerous shell glands enter the middle third of the 

 vagina. 



Distribution. — Florida, North Carolina, rather rare. 



Habits. — Found mostly on oyster beds. 



Neotype. — Pearse's type specimen of ^''Stylochus -flo rid anus ^'' 

 U.S.N.M. No. 20187, becomes the neotype of Imagine ocidifera Girard; 

 sexual region of this specimen as serial sections, three slides. 



Remarks. — Comparison of the original description of Imogi/ne ocu- 

 lifera with Pearse's description of ''^Stylochus fjorklanus'''' leaves no 

 doubt of the identity of the two species. Pearse gave no grounds for 

 placing the species in the genus Stylochus. As the genera of the 

 Stylochidae cannot be determined v»'ithout serial sections of the copu- 

 latory apparatus, it was necessary to have sections of a mature worm. 

 After sections of the sexual region of two specimens showed them to 

 be immature, it was unavoidable to remove and section the sexual part 

 of the type specimen. These sections showed that the animal is a 

 Stylochus., and hence Girard's genus Imoglne becomes a synonym of 

 Stylochus. 



