332 Anatomical Notes on Sutroa Alfcstris. [zoe 



Note. — I have been asked to describe the manner of collecting 

 and temporarily preserving the fresh-water Ohgochaetse. Use a 

 small sieve for separating the worms from the mud. For preserving 

 most of the species alive for any longer time, use small tin boxes, 

 say two inches broad by three-quarter inch deep. In each box 

 place two or three pieces of sponge, which first must have been 

 thoroughly washed out with strong alkali. The sponge is saturated 

 with fresh water and the worms, freed from all mud, placed in the 

 box. To begin with, change the water in the sponge every day. 

 Later, when the excrements of the worms have been all ejected, one 

 change a month is enough in hardier species. There must be no 

 free water in the box, and not more than six worms in each. In 

 this way I have preserved worms alive for four months, and carried 

 them with me in my valise across the continent to be studied at 

 leisure at home. For instance: I have to-day before me alive a 

 •Criodrilus, or a related genus, which I caught in Mississippi River the 

 latter part of September, 1891, to-day being January 12, 1892. The 

 worm is yet as active as at first, but greatly emaciated from want of 

 food. The '' sponge box " is indispensable to the helminthologist. 



EXPLANATION OF THE FIGURES. 



Plate I. 



Fig. 7.— Ventral part of the body wall, showing the arrangement of 

 the various organs. 



R. s,— Receptacula seminis or spermatheca, opening into a central. 

 Sp, at— Spermathecal atrium. 



Ex. por.— Exterior pore of the spermathecal atrium. 

 Alb. gl— Albumen gland. 

 Sep. gl. — ^Testes. 



'C. p.— Copulatory glands surrounding the copulatory papilla, c. p. 

 Eff— Efferent funnels or ciliated rosette, the interior free opening of 

 the efferent duct. 



Atr— Atrium of the spermiducal ducts. 

 Ovd. — Oviducts. 



Ovd. p.— Exterior pore or opening of the oviduct. 

 V. d. — Efferent ducts. 

 Pros. — Prostata. 

 Test — Sperm-sacs. 

 Ovary — Ovary or ovisac. 



