From the posterior intestinal portal the intestine extends straight cephalad to the posterior end of the stomach, dorsal to which it forms a double loop, a wider one, _lp^3_, and a narrow one, _lp^4_. From the latter loop, _lp^4_, the intestine extends straight caudad, parallel and near to the straight region leading from the posterior intestinal portal, until it reaches the region of the loop _lp^2_, dorsal to which it forms a small loop, _lp^5_. From loop _lp^5_ the intestine, which is here of very small caliber, extends caudad for about 10 mm., where it forms another indistinctly double loop, _lp^6_. From loop _lp^6_ the large intestine, _il_, extends, with gradually increasing caliber, to the cloaca, _cl_, a distance of 10 to 15 mm. Except in the enlarged region near the pylorus the lumen of the intestine is almost obliterated by the folding of its thick walls, so that little or nothing can be told of its lining with the naked eye. A distinct mesentery holds the loops of the intestine in position and binds the entire enteron close to the dorsal body wall. Because of the lack of properly fixed tissue no sections of the enteron of this stage were made. REFERENCES 1. BRONN, H. G.: Klassen des Thier-Reichs. (Vols. on reptiles.) 1890. 2. CHAFFANJON, V.: Observations sur Alligator mississippiensis (Tractus intestinalis und Mesenterium). Ann. Soc. Linn. Lyon, vol. 28, p. 83 ff., 1881. 3. EISLER, P.: Zur Kentniss der Histologie des Alligatormagens. Archiv f. Mikr. Anat., vol. 34, pp. 1-10, 1889. 4. HERTWIG, O.: Comparative Embryology of Vertebrates. Especially vol. 2, pp. 1-241, 1906. 5. REESE, A. M.: The Nasal Passages of the Florida Alligator. Proc. Acad. Nat. Sc. Phila., 1901. 6. REESE, A. M.: The Development of the American Alligator. Smith. Misc. Coll., vol. 51, No. 1791, pp. 1-66, 1908. DESCRIPTION OF FIGURES 1-8, PLATES 1-15 [Transcriber's Note: The word "Plate" refers to the physical pages on which the Figures were printed. The word is not used as an illustration identifier. Based on the author's age at time of publication, "Miss C. M. Reese" is more likely to have been his sister than his daughter.] The surface views were drawn, under the author's direction, by Miss C. M. Reese. The first two of these views were copied, by permission, from S. F. Clarke; the others were drawn from the specimens themselves. All of the figures of any one stage are given the same number, followed by distinguishing letters, so that it is possible to tell at a glance what figures belong together. All of the figures except those from Clarke were drawn under a camera lucida. Figure 1. A surface view of an embryo, from the dorsal aspect, at the beginning of the formation of the enteron. Figure 1A. A sagittal section of an embryo of approximately the age of the one shown in figure 1. x 43. Figure 2. A dorsal view of an embryo with five pairs of mesoblastic somites.