1 68 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



more than a very short piece of it. Everywhere in the mass 

 were seen numerous minute lumens, so small that they 

 could barely be studied with the highest lens systems. The 

 lumen system in this species is racemose, very similar to 

 the stem of a bunch of grapes. The main lumen and the 

 branches are lined by narrow strands, the same as in D. 

 Michaelseni. In addition to these, the main lumen has 

 here and there minute epithelial cells; these, however, are 

 absent in the branches. Thus, D. Ud e z tsikes an interme- 

 diate position between the two other species mentioned 

 above. The variations in the position of the spermiducal 

 pores, ranging from XVIII to XXI, are also of the greatest 

 interest. It seems probable that when more species are 

 known, the genus Di-plocardia will prove to be of great 

 morphological interest. 



Diplocardia Garman . 



Definition. — Setse, eight, in four couples, lateral and ventral. Penial setae, 

 present or absent. Spermathecal setae, present or absent. Prostomium 

 divides somite I more or less. Clitellum saddle- or ring-like, generally 

 XIII-XVIII. Oviducal pores XIV. Spermathecal pores, two or three pairs, 

 either postseptal or preseptal. Spermiducal pores on XVIII, XIX, XX, or 

 XXI, according to species. Prostate pores on somites next anterior and 

 posterior to the spermiducal pores. The pores on each side connected by a 

 groove. A genital zone generally present, with or without papillae. Intes- 

 tine with two gizzards, generally in V, VI. CEsophagus either with or with- 

 out folds containing calcic concretions. Tubular intestine never with cal- 

 ciferous diverticles, as in Benhamia. A glandular crop sometimes in XIV 

 and XV. Sperm-sacs, one pair preseptal in IX, one pair postseptal in XII. 

 Two pairs testes in X and XI. Two pairs sperm-funnels in X and XI. 

 Prostates, two pairs opening anteriorly and posteriorly to the sperm-ducts. 

 Spermathecse, two or three pairs, each one with a diverticle near the center. 

 Dorsal vessel double or single. Nephridia and meganephridia generally 

 without ccelomic mantle. 



Habitat. — As far as known, the genus is confined to the 

 United States and to northern Mexico. 



The following subdivision of Diplocardia is based on the 

 location of the spermiducal pores: — 



