CHAP. VI.] 



HIRUDINEA. 



165 



bricus, and A. tetraedrus. 



LYIIL, p. 251. 



Michaelsen, W., Arch. f. Xaturg., 1892, 



11. Allurus putris : specimen having £ pores on 13th (instead of 

 1 5th) as an abnormality ; in it the other external generative organs 

 (and doubtless the internal also) were 2 segments higher than usual, 

 the ^ pore being on the 12th instead of 11th. Tuberc. pubert 

 26 — 28. Michaelsen, Jahrb. Hamburg, wiss. Anst., 1891, vm., 

 p. 8. Compare No. 109. 



12. Allurus sp. : specimen having 1. side normal; right side, £ pore 

 in 12th, % in 11th, clitellus and tuberc. pubert. one segment higher 

 than usual. Ibid. 



13. Enchytrceid.e. £ pore generally in the 12th segment. In 

 Buchholzia appendiculata (Buch.) it is on the 8th, as a specific 

 character. In Pachydrilus sphagnetorum (Vejd.) it is either 

 on the 8th or on the 9th, according to individual variation, the 

 other parts being then disposed as follows : 



4. 



o. 



6. 



Michaelsen, W., Arch./, mikr. Anal, 1888, xxxi. p. 493; see 

 also Jahrb. Hamb. wiss. Anst, vn. p. 8. 



Perichseta hilgendorfi, n. sp. Mich. 7 specimens. Variation in number of 

 spermathecal openings, as follows. 5 specimens had 2 pairs in the groove between 

 segments 6/7 and 7/8; 1 specimen had 3 pairs, between 5/6, 6/7 and 7/8; 1 specimen 

 bad only one, on the left side between 6/7, which corresponded internally to a single 

 spermatheca [other variations also observed in these specimens, fl.v.]. Michaelsen, 

 W., Arch. f. Naturg., 1892, lviii. p. 236. 



Perichseta forbesi (an Earthworm from New Guinea). In this animal a pair 

 of spermathecae is placed in the 8th segment and another pair in the 9th. Two 

 specimens only have been examined and in both of these an additional spermatheca 

 was found on the left side, internal to the other. In one individual the 5th sperma- 

 theca was in the 8th segment, and in the other it occurred in the 9th. Beddaed, 

 F. E., Pwc. Zool. Soc, 1890, p. 65, Plate. 



Aliolobophora lissaensis. Similar variation in spermathecae, Michaelsen, 

 W., Jahrb. Hamb. iciss. Anst., vm., 1891, p. 19. 



Hirudin e a. 



Hirudo medicinalis. The number of pairs of testes is 

 variable, but 9 pairs most often found. Of 31 specimens of this 

 species, 21 had 9 pairs, 6 had 10 pairs, and 4 had 9 on one side 

 and 10 on the other. Chworostansky, C, Zool. Anz., 1886, 

 p. 446. 



