112 STROPHOMENIA OPHIDIAN A. 



fibres attaching to the base, are probably retractors, the pressure of the blood 

 in the underlying sinus being responsible for the protrusion of the organ. 



The hermaphrodite gland holds the usual position and anteriorly extends 

 to a short distance behind the level of the union of the oesophagus and gut. 

 In all the specimens the sex elements are fully formed, some of the large ova 

 having been dehisced and carried into the pericardial cavity. Posteriorly the 

 gland gradually decreases in size finally passing into two long slender canals 

 that unite with the front end of the pericardium (Plate 13, fig. 2). This last 

 named cavity communicates posteriorly with the coelomoducts that extend 

 backward a short distance before proceeding forward. At first the epithelial 

 lining of these canals consists of low cells similar to those bounding the pericar- 

 dium, but these are soon replaced by others almost cubical in form supporting 

 an abundance of long cilia that continue to the seminal receptacles. These 

 latter organs consist of from fifteen to eighteen sacs attached by short ciliated 

 stalks to the gonoduct. In every case they were completely filled with sperma- 

 tozoa. 



The section of the coelomoduct, extending backward from the seminal 

 receptacles, is lined throughout with relatively high columnar cells filled with a 

 darkly staining granular secretion. Immediately back of the seminal receptacles 

 these are developed into several longitudinal folds that quickly disappear more 

 posteriorly. Still farther backward the two ducts unite a short distance in 

 front of their outlet and in this single canal the internal folds reappear and 

 persist to the cloacal cavity. 



Immediately ventral to the outer opening of the reproductive sj'stem is a 

 short diverticulum of the anterior wall of the cloaca (Plate 13, fig. 2, dt). Its 

 cells are cubical in form and essentially like those of the cloaca at this point, but 

 there is no sign of spicules or any secretion that indicates its possible use. 



Strophomenia ophidiana, sp. no v. 



One specimen of this species (Plate 1, fig. 2), attached to an alcyonarian 

 coral, Acanlhogorgia angustiflora, was taken off the southern end of Honshu 

 Island, Japan (Sta. 3755) in water 52-77 fath. in depth. It measured 43 mm. 

 in length and 2.5 mm. through the thickest part of the body. The color is 

 creamy white shading to very light brown in the neighborhood of the head. 

 A well-defined dorsal sense organ is present of the usual tj'pe. 



The cuticle is relatively thick, measuring on an average 0.19 mm., and rests 

 upon a thin hypodermal laj'er whose constituents present no especially note- 



