PLATE X. 



Fk;. 36. — The ventral portion of the body wall is cut open anil reflected to show the pericardial chamber. Natural 



size, 

 a. br. v., anterior branchial vein; in this ease collapsed and not forming an auricular expansion. 

 a. p. g., anterior pericardial gland. The one to the left lies naturally; the one on the right has been turned 



upward to show the anterior branchial vein. 

 H, heart, enfolded by the pallio-viseeral ligament. The septal artery runs over its ventral surface, suspended 



by a mesentery-like fold of the pallio-viseeral ligament, and through the posterior viscero-pericardial 



aperture, 

 j, junction of the body wall and the pallio-viseeral ligament posteriorly. 

 1, ligament from the ventral edge of the posterior renal sac extending along the body wall. 

 p. a., pallia] artery. 



p. br. v.. posterior branchial vein, partly expanded. 

 p. p.g., posterior pericardial gland, 

 p. v. a. b., posterior ventral aponeurotic band. 

 p. v. 1., pallio-viseeral ligament. The three apertures through it by which the pericardial and genital divisions 



of the ccelom are put in communication are at either side of and behind the heart, 

 p. v-p. ap., posterior viscero-pericardial aperture, 

 pyr. s.. pyriform sac 



r. s., anterior wall of the right posterior renal sac. 

 Fig. 37. — Renal appendages from the posterior wall of one of the renal sacs. X 2. 

 Fig. 38. — Male genital organs viewed from above anil in front. The anterior portion is represented as dissected from 



the body wall. Natural size. 

 ac. gl., accessory gland surrounding the vas deferens. 



ao, aorta, passing upward from the heart at the back of the hremocoelic membrane, 

 g. 1., genital ligament, 

 gas. 1.. gastric ligament. 



I, intestine, cut at the middle of the second loo].. 

 II., intestinal ligament. 

 P. ap.. external opening of the penis. 

 P. 1., left tube of the penis. 

 P. r., right tube of the penis. 



p-v. 1., pallio-viseeral ligament at its attachment to the posterior side of the heart. 

 pyr. ap., external aperture of the pyriform sac. 

 pyr. .-.. pj riform sac. 

 r., rectum. 



sep., septum dividing the spermatophore sac. 

 sp. s., spermatophore sac. 

 S. V., seminal vesicle. 

 T. ap., aperture of testis 



T. g., face of the testis which is pressed against the stomach. 

 T. 1.. face of the testis w hich is pressed against the liver, 

 v. d. 1 , proximal thin-walled portion of the vas deferens, 

 v. d.\ commencement of the thick-walled portion of the vas deferens, which extends from this point to the 



seminal vesicle, 

 x, thickening of the tissues of the genital ligament extending from the root of the siphuncle. 

 y, tunic of the accessory gland carried upon tin- back of the testis. 

 Fig. 39. — Female genital organs viewed from in front and above. The anterior portion of the ovary rests upon the 



pallio-viseeral ligament. The heart and auricles show through the viscero-pericardial apertures. Natural 



size, 

 ao. aorta. 



ex. ap., external aperture of the oviduct. 



g. I., attachment of tile genital ligament to the posterior body wall. 

 <jas, L, gastric ligament. 

 I. intestine. 



I.]., intestinal ligament. 



I a., June along which the hremocnelic membrane is attached centrally. 

 1. v-i>. ap.. left anterior viscero-pericardial aperture. 

 i e. , ary. 



i >\ . a]... aperture of the ovary slightly pulled away from the inner aperture of the oviduct. 

 ovid., thin-walled portion of the oviduct. 

 ovid. ap., inner aperture of the oviduct. 



ovid. pa]>.. plaited, freely projecting tip of tl viduct; the oviducal papilla. 



p. an., posterior auricle. 



pyr. ap . opening of the pyriform sue into the mantle cavity, 

 pyr. s., pyriform sac. 



r 1, ligament attaching the rectum to the pallio-viseeral ligament, 

 r. v-p. ap., right anterior viscero-pericardial aperture. 

 s. nodule in the genital ligament at the root of the siphuncle. 

 Km. 40. — Cartilage viewed from the anterior side. Natural size. 



e.. cephalic process. 



i., infundibular process. 



I. i., point of attachment of the levator of the funnel. 

 m. p., median process of the body of the cartilage. % 

 v. v', holes through the cartilage occupied by veins. 

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