Abt. 12. AN EARTHWORM OF THE GENUS DIPLOCARDIA SMITH. 3 



Holotij]M.— Cat. No. 19116, U.S.N.M. Paratypc.—ln collection of 

 the Avriter. 



Sagittal sections were made of one-half of the anterior 24 somites 

 of the specimen having the clitellum best developed, and this speci- 

 men was used as the type of the new variety. Transverse sections 

 were made of the anterior 25 somites of the other specimen which is 

 designated as the parat3'pe. The general condition of the reproduc- 

 tive organs of both w^orms indicate that they had passed the climax 

 of a state of sexual activity and that the reproductive organs are not 

 at a stage of maxinunn development. The new form agrees in sev- 

 eral important characters with Diplocardia keyesi.^ described by 

 Eisen (1896) from a specimen collected in Lower California. Since 

 there is agreement between the new form and Eisen's species in most 

 characters which usually serve as a basis for distinguishing between 

 species in this genus, it seems preferable to treat the new form as a 

 variety of the species mentioned. 



Eisen's original description included many details concerning some 

 of the organs and was accompanied by numerous illustrations. The 

 same species was later described more briefly (Eisen 1899) in a paper 

 which dealt in a preliminary way with all of the species of Diplo- 

 cardia known at the time, and which included descriptions of some 

 new species of that genus. In the following year Eisen (1900) pub- 

 lished a more extensive paper which contained descriptions of the 

 known species of Diplocardm and of still another new species. There 

 are several discrepancies between some of the statements made in the 

 original description of D. keyesi and those made in the two later 

 papers. Although no statement with reference to it is made in either 

 of the later papers, it is probable that some of the changes were in- 

 tended to correct errors made in the original description. In other in- 

 stances it is by no means clear which of the differing statements is 

 more nearly correct. 



EXTERNAL CHARACTERS. 



The two Texas worms are similar in size, about 80 mm. in length, 

 and have a maximum diameter of slightly less than 2 mm. The 

 type specimen has 139 somites and the paratype 146. (Eisen's speci- 

 men is stated in all tliree papers to be 70 nnn. by 5 mm. Figure 66 of 

 his first paper is described as of natural size, and is about 85 by 3 mm. 

 In the first paper the number of somites is given as 80 and in the 

 other two papers as 150.) The Avorms preserved in alcohol are pale 

 and without obvious pigment in the body w^all. Tlie formula aa : ah : 

 he : cd=^l : 2 : 6 : 2i/^ indicates the relative setal distances of a consider- 

 able number of anterior somites and is based on averages of several 

 measurements. In the vicinity of somite 25 the formula aa:ah: 

 ?>c: cc?=6: 2: 6 : 2 is more nearly accurate. (A similar formula 



