o84 SUMMAKY OF CURRENT RESEARCHES RELATING TO 



America, but possess well marked characters of their own. There is 

 little trace of affinity with the Terricola fauna of Eastern South 

 America, and the slight development of the species of Geoscolex and 

 Fimoscolex without sperm-pockets, as well as of species of Antcus with 

 less than seven pairs of chyle-pockets, affords a marked contrast with 

 the Eastern fauna, in which such species are dominant. The absence of 

 Megascolecidse is also remarkable, for the family Acanthodrilinae to 

 which they belong is numerously represented both to the north and the 

 south of the area. The introduced forms fall into two groups : European 

 species, e.g. Allolobophora fcetida ; and tropical forms, e.g. Amyntas (?) 

 indicus (Horst) and Benhamia affinis Mchlsn. The occurrence of the 

 latter East African species the author regards as a confirmation of his 

 view that all the species of Benhamia found outside Africa have been 

 introduced into the localities in which they are found; and that the 

 genus originated in Africa. 



North American Oligochsetes.* — Mr. Frank Smith describes as 

 Premnodrilus palustris g. et sp. n. a new form found in Florida. The 

 new form appears to be allied to Eclipidrilus and Mesoporodrilus ; and as 

 these latter genera are represented by only one species each, the author 

 suggests that it may be found necessary to unite the three forms in one 

 genus, though he is not as yet prepared to do this. The most 

 notable point of resemblance is the presence of sperm-reservoirs in all 

 three ; the differences are chiefly in regard to the number and position 

 of the nephridia and the characters of the reproductive organs. 

 Of the three, Mesoporodrilus and Premnodrilus are most closely related. 

 The distribution is interesting, in that Eclipidrilus has only been found 

 in California, Mesoporodrilus in Illinois, and the new genus in Florida ; 

 but the anomaly is doubtless to be explained as the result of the 

 imperfect investigation of the intervening areas. Apart from the three 

 genera named, the Lumbriculidaj are represented in North America by 

 two species of Sutroa and one of Thinodrilus. Of these, Thinodrilus 

 appears to be related to Lumbriculus, while Sutroa seems to connect the 

 group formed by Eclipidrilus, Mesoporodrilus, and Premnodrilus to the 

 European genus Bhynchelmis. 



Maclovia iricolor (Montagu).f— Dr. Arthur Willey has a useful note 

 on the synonymy of this species, one of the longest Chsetopods of 

 Plymouth Sound, and also gives a brief diagnosis. Part of the con- 

 fusion has arisen from the fact that Maclovia cohabits with a Lumbrico- 

 nerei-s (probably L. latreilli), which though smaller has a strong super- 

 ficial resemblance to it, and has been often confused with it. 



Variation in Number of Genital Pouches in Thalassema neptuni.*— 

 Mr. F. H. Stewart describes a case of five instead of four genital pouches. 

 An unpaired pouch seemed to be interpolated between the two normal 

 pairs. " If this be granted, it would have to be assumed either that a 

 segment which does not normally bear pouches intervenes between the 

 two which normally do, or that a partial duplication of the nephridia of 



* Bull. Illinois Lab. Nat. Hist., v. (1900) pp. 459-78 (1 pi.). 

 t Journ. Mar. Biol. Ass., vi. (1900) pp. 98-100. 

 % Ann. Nat. Hist., vi. (1900) pp. 218-9. 



