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



EXPLANATION OF PLATE XIL 



Argilophilus -marmoratus collinus, subsp. nov. 



Fig. 118. Apex of penial seta. 



Fig. 119. Anterior somites, ventral view. 



Fig. 120. Genital somites, ventral view. 



Fig. 121. Prostomium and somite IL 



Argilophilus marmoratus papillifer Eisen. 



Fig. 122. Prostomium and anterior somites. 



Ocnerodrilus occidentalis Eisen. 



Fig. 123. Anterior somites in longitudinal section, showing form and size of 

 septal glands and testes. No details are attempted. The sec- 

 tion passes through the centre of the pharyngeal part, but misses 

 the intestine, except at its junction with the diverticle. 



Ocnerodrilus occidentalis Eisen, arizoncs, var. nov. 



Fig. 124. Anterior somites, dorsal view. 



Fig. 125. Genital somites, ventral view, showing male pores and papillae 

 and setse ab in somites XVI and XVII. 



Fig. 126. A male papilla with setae pores. 



Fig. 127. The same papilla, side view, inner sac-like lumen, into which 

 open prostate and sperm-duct. 



Fig. 128. Outline of prostates and sperm-ducts at the male pore; dissected. 

 The ventral nerve-cord is twice as wide as the sperm-duct. 



Fig. 129. Anterior somites, longitudinal section. The details are dia- 

 grammatic. 



Fig. 130. Cross-section of the male pore; junction of prostate and sperm- 

 duct; slight widening of the sperm-duct near the male pore. No 

 details attempted. Zeiss D., Oc. 2. 



Fig. 131. Longitudinal section through the male pore; sp. d. , the wider lumem 

 of the two joined sperm-ducts. The fusion of the ducts takes 

 place at the point marked X ; c p., copulatory papilla. 



Fig. 132. One of the testes and sperm-sacs, longitudinal section. The part 

 of the sperm-sacs shown represents about one-half of the whole 

 sac as seen in succeeding sections. 



Fig. 133. Section of prostate, showing the two different kinds of cells in the 

 same row or layer. 



Fig. 134. Genital zone, longitudinal section in XV and XVI; gl. c, gland- 

 ular, horizontal cells. The epithelium is chiefly composed of 

 broad, posteriorly frayed cells, the ends of which project through 

 the muscular layers. Probably a sense-zone. 



