1)8 (;ai,ii'okma aiadiomv ok sciences. 



PLATE XXXIII. 



PHCJiNICODHILUS TASTE. 



17. Ijougitudiiiftl section of the aliincutivry caunl ((usoplmgiLs), in vi. e/i. iuucr lining epithelium, r//. glnndnhir 



cells, hi. blood siims. m. the two mnscnlnr layers, pt. peritoneal epithelium. 



18. Longituilinnl section of the pharynx, showing the ghimliilar ilucta aud ductules penetrating the pharyngeal 



epithelium. <■/. ciliated surface, n. ep. nuclei of epitlielium. dus. ductules, ilnrt. large duct fiom the 

 pharyngeal glands above the fesophagus. n. ep. cesophageal epithelium joining the pharyngeal ciliated 

 epithelium. 



19. Section of the body through one of the clitellar somites, a diagrammatic view, to show the relative size of the 



different layers of the body-wall. (/. c. dorsal vessel, .s. S. saculated intestine. »i. /. the muscular layers. 

 rl. c. clitellar cells, up. d. spermducts. c. v and n. c. ventral vessel and nerve cord. 



•20. .V diagrammatic section of the body in somite ix showing the relative size, etc., of the diverticnla and the 

 layers of the body-wall. d. v. dorsal vessel. .</<. s. sperm-sacs in somites ix and x. ilic. diverticula of the 

 intestine. i\ v. ventral vessel. )i. c. nerve cord. 



21. Section of body-wall of a uon-ditellar somite. _</. r. nniiillulfir glands. .i. r. supporting cells, t.m. trans- 

 verse muscular layer. I. m. longitudinal umscular layer. />r. peritoneum. 



KE11RI.\ McDONALDI. 



2.S. Ncphridium of Kirria MiDonaldi from one of the somites closely posterior to the clitellum. pr. s. peritoneal 

 sac with nuclei. The posterior end of this sac is not furnished with blood capillaries, c. hi. capillary blood 

 vessels, spreading principally through the peritoneal sac. a. I. anterior lobe. p. I. posterior lobe, nephr. si. 

 nephrostome. nephr. pr. nephropore. w. d. wide duct outlet, n. d. narrow duct. nee. neck of the 

 nephridium. hr. bridge, apr. spur. s. septum. 



PONTODRILUS MIOIIAELSENI. 



24. A specimen, natural size, having been slowly killed and extended. One of the largest specimens, the majority 

 l)eing only one-half as large. 



2"). The three anterior somites seen from the side. /)r. prostomium. per. peristomium. 



26. The anterior part of the worm more highly magnified, ventral view. rl. clitellum. ! male pore. splh. p. 



spermathecal pores, ov.p. ovipore. c.pr.m. cushion where ends the fan-shaped fascicle of prostate or arci- 

 forra muscles, c. c. exterior copulatory cushion. 



27. Part of the body-wall laid open and spread out to show the relative distances of the setie, the numerals 



indicating tin' nuuibcr of the seta. The ventral nerve cord is indicated. 



28. One of the seta' highly magnilied. 



