N o . 4 • ] ^OR TH-A ME RICA N EARTH WORMS. 1 6 3 



with or without papillae. Intestine with two gizzards, gener- 

 ally in V, vi. OesopJiagns either with or without folds contain- 

 ing calcic concretions, but never with calciferous diverticula, 

 as in Benhmnia. Sometimes a glandular crop in xiv and xv. 

 Sperm sacs, one pair pre-septal in ix, one pair post-septal in 

 xii. Two pairs testes in x, xi. Two pairs sperm funnels 

 in x, xi. Prostates, two pairs, opening anteriorly and poste- 

 riorly to the sperm ducts. Spennathecae, two or three pairs, 

 each one with a diverticulum near the center. Dorsal vessel, 

 double or single. Nepliridia, meganephridia, generally without 

 coelomic mantle. Acanthodrilidae. As far as known, conlnned 

 to the United States and to northern Mexico. 



The genus Diplocardia differs thus from AcantJiodrihis in 

 having two successive gizzards, Acanthodrilns having only one. 

 From Benhamia, which genus possesses two successive giz- 

 zards, three pairs of calciferous diverticula, and numerous micro- 

 nephridia, Diplocardia is distinguished by its meganephridia, 

 of which there are two in each somite, and by the absence 

 of calciferous diverticula of the tubular intestine. From both 

 Benhamia and Acanthodrilns, as well as from all other genera 

 of the family, Diplocardia is characterized by the position of 

 its male or spermiducal pores. 



Key to species of Diplocardia. 



I. Spermiducal pores in somite xxi, no penial setae. {Aleodrilus.) 



Sp. I. D. Keyesi (YA&tn). 



II. Spermiducal pores in somite x.\. 



Sp. 2. D- verrucosa Ude. 



III. Spermiducal pores in xix. 

 A. Spermathecae, two pairs. 



Sp. 3. Both pairs of spermathecal pores pre-septal, or posterior to the 

 setae ; sexual spermathecal setae present in viii and ix. 



D. Eiseni (Michaelsen). 



Sp. 4. The pair of spermathecal pores in viii are post-septal ; the 

 pair in ix are pre-septal. Sexual spermathecal setae in viii 

 and ix. D- Michaelseni n. sp. 



Sp. 5. Both pairs of spermathecal pores are post-septal, sexual sperma- 

 thecal setae in viii-x. D. Udei n, sp. 



Sp. 6. Both pairs of spermathecal pores are post-septal, no sexual 

 spermathecal setae. D. riparia Smith. 



