E V I O R A MeseeitTii of Coimparative Zoology Cambridge, Mass. October 21, 1952 Number 9 NEW SPECIES OF EARTHWORMS FROM THE ARNOLD ARBORETUM, BOSTON By G. E. Gates I. From Allolobophora caliginosa (Savigny) 1826 there have recently been split off: yl. nociurna Evans 1946, and A. iowana Evans 1948. The new species were thought to be distinguished by differences in location of first dorsal pore, extent of male porophores, etc., and es-pecially by number of segments. These characteristics had not previ-ously been given such weight in lumbricid taxonomy, may be subject to variation and, as in the case of segment number, may be tedious to use when dealing with large numbers of worms. While working on collections from the Arnold Arboretum and other localities near Boston, it was found that material with characteristic caliginosa tubercula pubertates could be rapidly sorted into two groups according to the presence or absence of genital tumescences on segment xxxiii. Further study showed that those specimens with tumescences on xxxiii were referable to caliginosa as apparently restricted by Evans after breeding the worms in the laboratory. The worms with no tumescences on xxxiii were found to be consistently distinguishable from caliginosa by the same sort of characteristics as in the case of nocturna and iowana and, as well as those species, worthy of specific status. Allolobophora arnoldi n. sp. Type. Museum of Comparative Zoology, cat. no. 4441. Length, 55-100 mm., diameter, 4-6 mm. Segments, 152-194 (normal specimens). Unpigmented and almost white, or of greyish appearance or, especially in older worms of second season, with a brownish coloration. First dorsal pore, on 10/11, 11/12, or 12/13. Clitellum, on xxvii, J/^xxvii, or xxviii to xxxiv or V2XXXV. Tubercula
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