MKRISTIC VARIATION. 



[PART i. 



in other genera and species. BEDDAHD, F. E., Proc. Zool Soc., 

 L886, p. ;<)>$, Hgs. 



FIG. 2.j. I'trimiyx excaratm. Diagrams shewing some of the variations in 

 n-.-jM.-ct of the number and positions of the openings of the spermathecte and 

 p-in-i;itive pores. From BKUDARD, P. Z. S., 1886. 



Perionyx griinewaldi, Michaelsen. Normally a pair of male 

 l pores on the IStli segment, and a single oviducal opening 

 fur tin- two oviducts in the middle line of the 14th segment. 



107. In two specimens a dim-rent arrangement was found. One of 

 the-c had the oviducal opening in the 15th segment [position of male 

 openings not specified and presumably normal]. 



10s Tin- other had two oviducal openings, one in the 13th and one 

 in the 1 1th segment [not stated whether these openings were median 

 or lateral, nor whether each of them was a double structure as of 

 course tin- normal female opening is]. In this specimen the male 

 i. Innings also were placed anteriorly to their normal position, being 

 in the 17th segment. M icn AF.I.SKN, ./<//*///. <1. Hamburg, wiss. Anetalt, 

 1801, VIM., p. 34. 



A 1. 1. 1 IMS. In Terricohe generally, the pores are on the 15th, 

 ami the ^ pores on the 1 1th, as in the common Earthworm. 



K)!t. Allurus tetraedrus, a widely distributed form, has pores on 

 the liitli and J pores on the 14th, the pores being thus in front of 

 tin- J pores as a specific character. I'nder the name Allurus dubius 

 .Michael.sen described two specimens having the male pores on the 

 1 1th in.-t.'ad of on the li'.th. ami the pores on the 15th instead of 

 on the 1 Ith, i-adi lii-ing thus one segment in advance of its normal 

 place [backward Honm-osis]. MICHAKLSKN, \V., Ja/trb. Hamb. u-is*. 

 .!//>/., l' s '.'U, VII., ]>. 7; see also Arch. f. Natury., 1892, LVIII., 

 p. '_'"' 1 . ( 'omjiarr No. III. 



II". 1'iesides these is a batch of S specimens of A. tetraedrus, loc. un- 

 known, (! specimens had both and J pores in the 14th. Clitellum 

 began in 'J.'inl, tuberc. pubert. in L'lth. These specimens are thus 

 intermediate between A. // /vy/m/x, which has the pores as in Lum- 



