Il6 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



variety to be merely a form of Ocnerodrilus occidentalis. 

 The septal glands in VII are larger than in the variety 

 arizon(2. 



Septal formula: — 



V/VI, VI/VII, VII/VIII, VIII/IX, IX/X, X/XI, XI/XII, 



XII/XIII. 



Ocnerodrilus occidentalis Eisen, arizonae, var. nov. 



Plate XII, Figs. 124-134. 



Definition. — Size 15-25 mm. Clitellum 1/3 XIII-1/2 XX. Setag ab in 

 somite XVII both present. No spermathecae. Testes, two pairs in X and 

 XI, directly capped by two small sac-like sperm-sacs in X and XI. No race- 

 mose sperm-sacs. Sperm-ducts not greatly enlarged near the male pore, but 

 with a slight swelling of the lumen. Prostate and sperm-ducts joining in the 

 same pore between the longitudinal layer and the epithelium. Prostates 

 small, not extending beyond the clitellum. Septal glands of unequal size, the 

 posterior ones much smaller. Diverticles of the oesophagus not divided into 

 chambers. Sacculated intestine in XII. 



Habitat. — Phcenix, Arizona, near irrigation ditches. 

 Obtained through the kindness of Mr. Geo. A. Treadwell, 

 October 19, 1896. A number of specimens have since 

 been received from the same locality, collected by Master 

 Grant, in January, 1897. 



The variety differs but slightly from the species, but I 

 believe the differences are worthy of being recorded, 

 especially those concerning the size of the suprapharyngeal 

 glands. 



Ocnerodrilus occidentalis. Ocnerodrilus occidentalis, 



var. nov. arizonce. 

 Septal Glands. 



Of about the same size. The most Of different sizes. The posterior 

 posterior pair of glands not smaller pair of glands is very much smaller 

 than those anterior to it. than those anterior to it. 



Prostates. 



Long, extending backward through Short, confined to the clitellar 

 several somites behind clitellum. somites. 



Both species and variety differ from all other species of Ocnerodrilus in the 

 absence of spermathecce and racemose sperm-sacs. 



