470 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 85 



Immediately anterior and just posterior to each male pore is a 

 transverse^ oval genital markinof, about 1 intersetal interval wide, 

 with a thick whitish rim and a grayish depressed center. Just in 

 front of each anterior marking and just behind each posterior mark- 

 ing is a raised, transversely oval, whitish (glandular ?) patch. The 

 centers of these patches are very slightly median to the centers of 

 the genital markings. The centers of the genital markings are about 

 in line with the male pores. There are two pairs of preclitellar 

 genital markings, presetal on xii and xiii. These markings are 

 round to transversely oval, about 2 intersetal intervals wide trans- 

 versely, the markings of a pair separated by a midventral distance 

 slightly greater than aa. Each marking has a flat grayish center, 

 which is wider than the central portion of a postclitellar marking, 

 and a whitish rim. The markings are slightly nearer to the setae 

 than to the intersegmental furrows. 



Intei^ial atuitoniy. — No septa are thicklj^ muscular; 8/9-9/10 

 lacking. 



The intestine begins in xvi. The intestinal caeca are simple, con- 

 stricted slightly by the septa through which they pass. 



The last pair of hearts is in xiii. All hearts of ix-xiii pass into 

 the ventral vessel. 



The testis sacs of x and xi are unpaired and ventral. The anterior 

 margins of both sacs are bilobed. The seminal vesicles of xi and xii 

 are fairly large, in contact transversely above the dorsal blood vessel. 

 The prostates are confined to xvii-xviii. The prostatic ducts are 

 about 3 mm long, of nearly the same thickness throughout, bent 

 into a C- or a U-shape. 



The spermathecal duct is shorter than the ampulla and is narrowed 

 within the parietes. The diverticulum passes into the duct close to 

 the parietes and comprises a short, slender stalk and a thicker, longer 

 seminal chamber that is twisted into a mass of loops. There are 

 masses of iridescent material (spermatozoa) in the seminal chambers. 



Remarks. — There are cystlike bodies on the spermathecal seminal 

 chambers, probably abnormal. Possibly some of the supposedly spe- 

 cific characters of this worm are also abnormalities. 



P. pomella is distinguished from P. planata Gates, 1926, by the 

 more posterior location of the spermathecal pores, the posterior loca- 

 tion of the preclitellar genital markings, the absence of copulatory 

 chambers, and the ventral testis sacs. 



