100 CALIFORNIA ACADEMY OF SCIENCES. 
PLATE XXXIV. 
PONTODRILUS MICHAELSENI. 
29. A somewhat diagrammatic view of the anterior somites seen in longitudinal section. br. brain. mo. mouth. 
ph.c. pharyngeal cavity. pha. pharynx. m. muscular strand connecting pharynx with the body-wall. s/. gl. sal- 
ivary or pharyngeal glands opening by ducts in the pharynx, the ducts being supported by muscular strands 
(stained yellow). ss. g/. smaller gland; connected with blood vessel. g/. glands connected with the lateral vessels. 
@. esophagus. d.v. dorsalblood vessel. s.septa. spth. spermathecm, and their diverticula. The lower end 
of the spermatheca is greatly enlarged, forming propulsory bursa. spth. p. spermathecal pore. ¢. testes. 
ov. ovaries. ovd. oviduct. c. 7. ciliated rosettes. A. hearts. sp. s. sperm-sacs. These sacs are principally 
yentralto the esophagus. nephr. nephridia, the most anterior one is foundin somite xiii. c/. clitellum. gl.cr. 
glandular crop in shape resembling a gizzard. s. 7. sacculated intestine. pr. prostate. ¢ the muscular duct 
of the prostate ent through. c.c. copulatory cushion. The dotted line indicates the outlines of the duct as 
they appear in other sections. 
30. Section through the posterior part of the pharyngeal glands, showing the arrangement of the glands, ducts, 
muscles and blood vessels, all in vertical section. «@. cesophagus. ep. inner epithelial lining. m. @. cireular 
cesophageal muscles. m. muscular strands. pha. gl. pharyngeal gland. d.v. dorsal vessel. 
In this figure the glands are stained violet, the muscles appear as yellow and the duets are dark violet. The 
blood vessels are black (Corosive sublimate, abs. alcohol, orange G. amm. hematoxylon. Thus in xylol. 
This and the following five figures are all drawn from sections treated in the same way.) 
31. A longitudinal section of a lobe, showing the general arrangement of the glands and ducts. duc. ducts from 
the gland, leading anteriorly to the pharynx. gl. c. glandular cells. O/. gl. blood glands. m. supporting 
muscular strands. b/. v. blood vessels. 
32. A small glandular lobe more highly magnified. The letters indicate the same as in the preceding figure. The 
nuclei are stained yellowish with orange G. The secretion of the cells is precipitated? and stained dark violet 
with amm. hematoxylon. 
33. <A part of a gland, with supporting muscles. 
34. Two sections of muscular strands, showing the connection with the ducts in which the secretion has been 
stained deep blue. 
35. One of the glandular cells with nucleus stained yellow. ‘The vacuoles (va.) are white, the protoplasm grayish, 
while the secretions are stained deep bluish-violet. 
36A. The proximal end of two glandular ducts where they penetrate the epithelial lining of the pharynx, near its 
dorsal side, showing the ductules or end ducts leading between the epithelial cells. 6/. blood vessels. m. ph. 
supporting muscles for the ducts connecting with pharynx. ¢. m. transversal muscles cut across. gl. d. 
glandular ducts leading from the gland at the distal end beyond the pharynx. These ducts are the largest 
and collective ones, having received the secretion from many smaller ducts. ep. epithelial cells lining the 
pharyngeal cavity. g/l. dt. glandular ductules passing between the former into the pharyngeal cavity. s. gl. 
two of the smallest of the salivary glands, a few of which are found at the periphery of the pharynx. 
36B, A longitudinal section of one of the small septal glands, one pair of which is found in y, vi, vii, viii, ix. 
c. bl. v. connecting blood vessel between the ventral vessel c. bl. vi and the dorsal vessel. This vessel is 
cut in two places, the one marked c. b/. vii being nearest to and just below the esophagus (@. v.) the ventral 
outline of which only is figured diagrammatically. s. septum, outline of, between yi/vii. g/. small glands, a 
few of which surround the somewhat larger septal gland. ss. gl. the largest septal gland. w. c. wandering or 
perigastric corpuscles. d. ¢. discharge ducts from glands, probably connecting with the pharynx. 
37. Cross-section of an immature specimen, through the intersegmental groove between somites xyii/xvili, just 
anterior to the copulatory cushions. In this section no clitellar cells haye yet developed on the ventral side 
of the body. hy. hypodermis. ¢. m. transverse muscular layer. /. m. longitudinal muscular layer. neph. 
nephridium. s. a. septum between xyii/xviii. m. muscles connecting the glandular part of the sperma- 
theca with the body-wall. g/. pr. glandular part of the prostate. spd. the sperm-duct just entering the 
glandular prostate. m. pr. muscular part of the prostate. v. ne. ventral nerve cord. s. 7. sacculated intes- 
tine. 
38. Cross-section of the body of an immature specimen, through somite xviii, the section passing through the 
copulatory cushions and through a part in which the clitellar cells on the ventral side of the body are already 
developed. a. m. arciform muscles connecting the copulatory region with the dorsal part of the body-wall. 
cl. c. clitellar cells developed in this somite only on the ventral side, neyer extending to the dorsal side even 
in fully mature specimens. Other letters indicate the same as in the preceding figure. 
39. Cross-section through somite xiii close to the anterior septum. The clitellar cells are here fully developed. 
s. 8. part of septum between xii/xiii. e/. ¢. clitellar cells, only developed dorsally. v. ¢/. ventral termini of 
the clitellar cells. ov. ovaries. spd, spermduct. ¢. i. tubular intestine. dv. dorsal vessel. fA. hearts. 
