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Show 1890.] HELODERMA SUSPECTUM. 201 In my larger specimen the ovaries are very much atrophied, while the oviducts have very much more the form of those in Lacerta viridis, as drawn for us by Parker in his ' Zootomy,' than they have in L. muralis as seen by Parker (W. N.), and figured in his translation of Wiedersheim's ' Comparative Anatomy of Vertebrates ' (p. 318). In other words, their anterior ends are rather split-leaf like than elongo-folded tubule-like. A comparison of the two figures in question will make m y meaning clear. The kidney is large and several-lobed rather than two-lobed as it is in Lacerta viridis, and its posterior slender part equals in length the anterior or enlarged part. The ureters open in the usual way in the cloaca. In Heloderma the kidneys are of about an equal size, and each one extends about as far forwards as the other. Standing between the anterior aperture of the oviduct and the atrophied ovary in my larger specimen, I make out a parovarium, which is thin and subcircular and about as large as m y index-finger-nail. Leading backwards from it, I can with ease trace the rudimentary duct of Gartner. Upon either side, at the sites of the penes in the male, I find present a papilla which possibly represents a clitoris in this lizard. V. NOTES UPON THE THORACIC ORGANS. Upon opening the cavity of the chest we find a very firm pleuritic membrane, continuous with the serous membrane covering the liver, spreading across the heart from lung to lung and enveloping those organs, as well as enclosing the structures about the heart's base. Dividing this down the median line we observe that the last-named organ is likewise contained in its own serous sac, the pericardium, while our dissections further show that the outer membrane closely ensheaths the lobulus cardiacus of the liver and the thyroid gland at the ventro-posterior end of the trachea (see figure 3 of Plate XVI., I.e., t.g.). Opening next the pericardium the heart is brought fully into view, with its ventricle and two large auricles. The Thyroid Gland.-This structure is quite large in our present subject (fig. 3, t.g.), and occupies a very different position from the thyroid in such a reptile as Lacerta viridis. In Heloderma I find it at the root of the trachea overlying the great vessels at the base of the heart. This is more in a'ceord with what we find in Birds, where in some forms of them it lies upon, the origin of the carotid artery; there is, however, a gland upon either side at the base of the thyroid in a young Stork 1. As in the Crocodiles, the thyroid of Heloderma is bilobed ; the transverse, basic portion lies across the trachea next the base of the heart, and connects the two lobes. These are subcylindrical in form, with pointed apices, each passing forwards by the windpipe, on either side. 1 See Wiedersheim's ' Comparative Anatomy of Vertebrates,' Engl. ed. by W. N. Parker, p. 227, fig. 185 (tr.). |