AQUATIC EARTHWORMS 6^^ 



41 (40) Spermathecae withoul diverticula, paired or two unpaired ones 



opening separately; long, highly muscular, ejaculatorv 

 chamber forms part of each otherwise highly difrcrcntiatcd 

 sperm-duct EclipiJrilus Eisen 1881. 



A genus of peculiar North American Lumljriculida,- which includes /•. fnnJus Fism 

 from Cahfornia, with paired $ pores on X; E. asymmetricus (I-rank Smith/ from IIIinST 

 with single median ^ pore on X; and t. palustns (Frank Smith) fr(.m Florida with wirH I 

 pores on IX (Smith, igooa). i^ucu ,5 



42 (36,37) Earthworms, essentially aquatic in habit. Setae simple-[M)intcd 



and paired in each of four bundles per somite; i jM^res ex- 

 ceptionally on XII or XIII, commonly further jxjsterior- 

 spermaries in X and XI; ovaries in XIII 43 



43 (44) Clitellum beginning on XIV to X\T and extending over 10-12 



somites; $ pores on XVHI/XIX or on XIX. recognizable 

 only in sections; few or no dorsal [)()res; without well- 

 developed gizzard Sparganophiliis Benham 1892. 



Several North American species, of which S. eiseni Frank Smith is found in the Mi«isissinpi 

 Valley, Great Lakes region, and Florida; S. smithi Eisen and subspecies occur in Caiifomia 

 6". benhami Eisen and subspecies in Mexicoand Central America (Eisen, i8g6). 



44 (43) Clitellum beginning on XVIII-XXIII and extending over 4-6 



somites; ^ pores on XII, XIII, or X\', conspicuous; gizzard 

 limited to XVII; first dorsal pores on I\'/\'. 



Hdodrilus Subgenus Eiscnidla Michaelsen kjoo. 



The highly variable species, H. (E.) tetraedriis (Savigny), is represented in North A merit a 

 by several of the subspecies indicated in the diagram from Michaelsen (Fig. 9^3). 



12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 2S 



furm tjfica 



furm hcrcynxa 

 form tura/x^itiina 

 furm .\'iHnii 



fulin ylv/ii 



Fig. 993. Different forms of Heloirilus {Ehenidla) tctraedrus (SaviRny). The diaKram shows 

 the positions for the spermiducal pores and the tubercula pubertalis. (.\ftcr Michaclicn.) 



A specimen which is presumably the type of Ilclodrilus tclrarJrus forma pupj (Eis<-n) 

 was deposited in the United States National Museum and has been studittl by the writer 

 It is almost certainly a regenerated individual and is hii^hly abnormal and hence the form 

 presumably has no systematic status except in synonomy. References in |>ara>iraphs 42 and 

 44 of the above key and in Fig. 993, to spermiducal pores on XII, have therefore lost their 

 significance. 



Beside these essentially aquatic forms, several species ji Diplocardia and HciodrUus live 

 in bottomlands and low-lying banks of streams which are subject to overflow for prolonged 

 mtervals 



— • ^^ 



^^ f~ 



— ;• ^ 



-p* ^ ^^ — 



-y II — 



