50 PROCEEDINGS OF THE NATIONAL MUSEUM vol. los 



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was introduced into the United States in shipments of nursery stock, 

 and Schread (1952) beheves that human agency alone can account 

 for its present distribution through the medium of turf transports 

 from one golf course to another. 



The anatomical study presented here represents the first phase 

 of an investigation that has covered physiological and ecological 

 problems as well. The anatomy of the worm has been reexamined 

 with special reference to variation in size and form, and only those 

 morphological characters are described in detail where they vary 

 from the descriptions of other workers. Bahl's (1950) memoir on 

 the Indian earthworm Pheretima posthuma has been an extremely 

 valuable reference. Specimens of P. hupeiensis used in the present 

 study have been deposited in the U. S. National Museum, Washington, 

 D. C. 



Appreciation is expressed to Dr. Roger B. Friend, Dr. G. E. Pick- 

 ford, and Prof. G. E. Hutchinson for their counsel during the course 

 of this study. 



Methods: All measurements and dissections were made on speci- 

 mens swept from the greens of the Pelham Country Club, Pelham, 

 N. Y., on July 7, 1949, or on specunens collected from the nursery 

 plot at the same location on various occasions between July and 

 October 1952. Because of the differential contractility of anesthetized 

 individuals, all measurements of width and length were made on 

 specimens preserved in the field in 4 percent formalin, in which it was 

 hoped that the degree of contraction would be uniform. Widths 

 were taken with calipers to the nearest 0.5 mm. in the region of the 

 worm just posterior to the male pores and genital papillae. 



Before sectioning in the laboratory the animals were kept on damp 

 cheesecloth or in aerated tap water for several days in order to allow 

 evacuation of the gut. Worms were then fixed in Petrunkevitch's 

 sublimate fluid for 24 hours, sectioned, and stained with hematoxylin 

 and eosin. Whole mounts of spermathecae, prostates, etc., were 

 made of organs fixed in Petrunkevitch's fluid and cleared in amyl- 

 acetate. In order to examine the internal sexual structures it was 

 necessary to reverse the normal procedure and dissect worms from the 

 ventral side. 



Before analysis all specimens to be examined were placed in the 

 following categories: 



1. Mature. Clitellum fully developed. 



2. Semimature. Clitellar segments distinct but with all setae and dorsal 



pores still visible. 



3. Immature. Clitellar segments not differentiated. Male pores and genital 



papillae well developed. 



4. Juvenile. No diflferentiation of clitellar segments and with male pores 



and genital papillae lacking or indistinct. 



