VOL. II.] Anatomical Azotes on Sut7'oa Alpestris. ' 329 



terior part, possibly in somite XYIII. The prostata is attached 

 to the posterior part of the atrium, extending through seven somites. 

 It must be considered as one continuous gland, although it is con- 

 tracted at every dissepiment and similarly enlarged in the center of 

 each somite (Fig. I, pros.; Figs. 12 and 13); thus forming a num- 

 ber of sacculated pockets. These contain glandular agglomera- 

 tions of pear-shaped cells (Figs. 12 and 13). The posterior part of 

 the prostata is completely covered by the sperm-sacs, to such an 

 extent that it is extremely difficult to observe and dissect them. In 

 the XII somite the prostrate is generally free, and it is here easy to 

 observe the difference in structure between this organ and the 



sperm-sac. 



The funnel-shaped openings of the efferent ducts (Fig. i, eff), 

 are seen immediately behind the copulatory papilla and are gen- 

 erally found full of protruding spermatophores. The copulatory 

 papilla opens in the center of segment IX (Fig. i). It is here 

 surrounded by from two to four or more glands (Fig. 2), which 

 open through the body wall at the base of the papilla (also Fig. 3). 

 These glands vary in size and number, but are often equal to the 

 diameter of the papilla. In the interior of this papilla is seen the 

 extreme end of the atrium, which projects from the w^all of the 

 papilla and forms a distinct copulatory organ (Fig. 2, p.). At 

 copulation the whole papilla becomes inverted and projected out- 

 side of the body (Fig. 3, p.), thus forming a distinct exterior copu- 

 latory organ. 



Spermatheca. The receptacula seminis or spermatheca^ ar^ 

 somewhat similar to those of Sii/roa rostrata. While in Rhynchel- 

 mis there exist one pair of spermatheca In somite IX, opening 

 behind the vertral setce, Sutroa possesses only" one solitary sperma- 

 thecal atrium opening In the center of somite \TL 



The spermathecal-porus opens immediately under the ventral 

 ganglion which is, in order to give room, slightly pushed towards 

 the left (Figs, i and 7). In my description of Sutroa rostrata I 

 ascribed to this spermathecal atrium the properties of an albumen 

 gland, but a further consideration of this organ in our present 



•In this paper I have to a great extent adopted for the organs the nomenclature 

 proposed by Benham. See " An Attempt to Classify Earthworms" by W. B. Ben- 

 ham, Quatr. Journal of Microscop. Science, xxxi, p. ii, page 201. 



