KM CAI-H'OltMA ACADKMY OF SflENC'ES. 



PLATE XXXVI. 



I'UNTODKILUS MICHAELSENI. 



46A. Scrtion thi'ovish tlio rudiiiu-utiiry gizzard or thickening of the iutcstiiml wall in soniitf v. * 



4(iB. One of the circuhir muscular strands of the former figure. 



46C. Section of the alimentary wall adjoining posteriorly to the rudiuicutary gizzard in somite vi. 



4T. .\ loiigiindiual section through the intestine showing the glandular-crop in somites xiv, xv, xvi, and the be- 

 ginning of the sacculated intestine in xvii. d.v. dorsal vessel, d. r. c. connection between the dorsal vessel 

 and the vascular system of the crop. ijt. rr. glandular crop. hi. k. blood sinns in the outer layer of the 

 glandular layer, gl. c. glandular cells constituting the bulk of the crop. elo. chloragogeu cells, hi. I. the 

 two muscular layers, t. i. the end of the tubular intestine or cesophagus. 



48. A section of the former more highly magnifitd, showing the glandular cells which constitute the crop and the 

 branched lumens which are especially ]>rouounced in the outer part of the layer. /.»«., (. ni. the two mns- 

 cular layers, which here are not more developed than in any other i)art of the intestine. 



40. Cross-section through the glandular crop iu the posterior part of the organ in somite xvi. In this section only 

 few of the glandular cells are found. 



50. A section anterior to the former, but in the same somite. Here many more of tlic glandnlar cells arc seen. Iu 



these two sections the chloragogen layer is thick and the cells crowded, similarly the ridges of the epithelial 

 cells aie high and separated by deep grooves. 



51. A similar cross-section through the crop in somite XV. Both the chloragogen cells and the epithelial cells are 



lower. 



.VJ. .\notlicr cross-section showing the entrance of a blood vessel from the dorsal vessel into the vascular system 

 of the glandular cro)). 



5.'}. .\ part of the glandular cells of the crop more highly maguilied showing the strncture of the colls and the 

 branched lumens between them. fjl. c. glandular cells. /. lumen, hi. blood sinus, cp. inner epithelial 

 cells. 



54. An oblicjue section through the surface of the crop showing the two muscular layers, a blood siuns and a few 

 chloragogic cells cut through. The glandular cells immediately below are not delineated. 



