932 The American Naturalist. 
[November, 
the first and last arches, only a trace of them being observable on the fifth. Sin Hyrtl 
studied the miterial after Bischoff had dissected it, it seems probable that these gill 
filaments, being tender in nature, were broken away during the previous study, leav- 
ing only the “ fadenfórmigen Zotchen" found by Hyrtl. 
€ Parker, W. N., Anat., Physiol. of Protopterus, Trans. Irish Acad., 1892. 
"Owen, R., Comp. Anat. Vertebrates and Description of Zegidosirem annectens 
Trans. Linn. Soc., XVII. 
* Giglioli, Lepidostren paradoxa, Nature, 1892. 
? McDonnel, Anatomy and Physiology of Loidivisn en annectens, 1854. 
1? Bischoff, Th. L., Lepidosiren paradoxa, Leipzig, 1840. 
11 Hyrtl, J., Zepidosiren paradoxa,1845. 
12 Klein, Beiträge zur Anatomie d. Lepidosiren annectens, Jahrb. d. ver. f. Naturk. in 
Würt., 1894, XX. 
13 Burckhardt, R., Das Nervensystem der Dipnoern (Protopterus annectens) 1892. 
* Wiedersheim Grundriss der vergl. Anat. 2te ed. 1893 
