POLYCLADS OF W. INDIES AND FLORIDA — HYMAN 119 



able. There appears to be a common sperm duct with rather thick 

 walls; this could be seen above the prostatic vesicle but could not be 

 traced definitely into it although there is little doubt that it must 

 enter the dorsal wall of the vesicle. There are no indications of a 

 seminal vesicle in any of the three known species of this genus, but 

 one of the other species has spermiducal bulbs. There was no indi- 

 cation of these in antillarum. A small accessory male gonopore close 

 to the main gonopore occurs in the two other species of Adenoplana 

 but is wanting in antillarum, at least in the available specimen. 



The female apparatus differs markedly from that of the other 

 species of the genus. The female gonopore lies well behind the male 

 pore (fig. 81,6) and leads into a broadly tubular antrum that enters 

 the middle of an expanded, dorsoventrally flattened cement pouch. 

 This pouch is surromided by a cloud of cement glands whose granular 

 secretion fills its epithelial lining. From the anterodorsal region of 

 the cement pouch, the vagina proceeds dorsally as a tube that soon 

 turns posteriorly, lying above the cement pouch, and enters the middle 

 of the ventral surface of the sacciform Lang's vesicle. This vesicle 

 consists of a tall ciliated epithelial wall. The beginning of the vagina 

 is slightly expanded and also ciliated. The entire female apparatus 

 is wanting in muscularity. The entrance of the oviduct into the 

 vagina could not be found. 



Differential diagnosis: Adenoplana antillarum differs from the 

 other two known species of the genus — A. obovata (Schmarda), 1859, 

 redescribed by Stummer-Traunfels, 1933, and A. evelinae Marcus, 

 1950 — in body shape, eye arrangement, details of the female apparatus, 

 and lack of an accessory male pore. Both these species are of broadly 

 oval form with definite tentacular and cerebral eye clusters and an 

 extended margmal band of eyes, and in both the female apparatus 

 lacks a cement pouch and has a crescentic Lang's vesicle. They 

 further are provided with a very small male pore alongside the 

 principal one. 



Distribution: Collected by W. L. Schmitt on the Smithsonian- 

 Hartford Expedition (specimen No. 23) at Charlotte Amalie, St. 

 Thomas, Virgin Islands, Apr. 4, 1937, on shore of harbor. 



Holotype: Anterior part as whole mount, posterior part as sagittal 

 sections (2 slides), deposited in the U. S. National Museum, No. 24630. 



Remarks: Although the male apparatus of the specimen agrees 

 well with that of the other species of the genus, the specimen differs 

 so much from them in body shape, eye arrangement, and details of 

 the female apparatus that it will be desirable to remove it to a new 

 genus if similar species are found. 



