464 PROCEEDINGS OF THE NATIONAL MUfiEUM vol. 89 



Color. — Dorsal surface with striking color pattern of brown on a 

 flesh ground, similar to pattern of S. zebra; wide brown middorsal 

 area interrupted by spots of ground flesh color; from this brown 

 rays extend in groups to margin (fig. 26, a). 



Digestive system. — Could not be seen because of pigment. 



Reproductive system. — Sexual region removed and sectioned 

 sagittally. Copulatory apparatus (fig. 26, 6) typical of the genus 

 Stylochics. Vasa deferentia seen in living animal proceeding back- 

 ward from about middle of body. As they approach the copulatory 

 apparatus they acquire a thick muscular wall and hence are acces- 

 sory seminal vesicles. Copulatory apparatus in last fifth of body, 

 about 6 mm. from posterior end. True seminal vesicle bulbous, some- 

 what erect; accessory seminal vesicles course along its anterior end 

 before entering, producing tripartite seminal vesicle common in many 

 species of Stylochus. From seminal vesicle muscular sinuous duct 

 proceeds backward to enter duct of prostate vesicle. Prostatic vesicle 

 large, oval, horizontal, with moderately thick muscular coat, and 

 chambered interior; wall penetrated by ducts of extracapsular pro- 

 static glands. Duct of prostatic vesicle runs directly ventrally, re- 

 ceives seminal vesicle; beyond this junction, canal becomes lumen 

 of very slightly developed penis papilla ; pyrif orm male atrium leads 

 to male genital pore. Female genital pore shortly behind male one; 

 vagina simple curved tube; proceeds dorsally, then curves backward 

 to receive uteri; numerous cement glands along its course; vagina 

 but slightly muscular. 



Diffei^ntioH diagnosis. — Stylochus jndcher differs from other mem- 

 bers of the genus in the color pattern, poor development of marginal 

 band of eyes in the posterior half, and extremely small penis papilla. 



Distribution. — Collected at Beaufort, N. C, dredged in 60 feet, in 

 a snail shell occupied by a hermit crab. 



Type. — ^Whole mount; copulatory apparatus as serial sections; 

 U.S.N.M. No. 20531. 



Remarks. — Tlie possibility that this species might be merely a 

 color variation of 8. zebra was dispelled by study of the copulatory 

 apparatus, which is obviously different from that of the latter. 



STYLOCHUS OCULIFERUS (Girard, 1853) 



FiQURKs 27, 28, a 



Imogine oculifera Girvrd, 1853, p. 367. 

 Stylochus ocuUferus Diesino, 1861, p. 570. 

 Stylochus floridanus Pe.vese, 1938, p. 71, fig. 24. 



Material. — Five whole mounts in Pearse collection, including type 

 of Stylochus -floridanus; sexual region of three removed and 

 sectioned. 



