LEPIDOSLREX PARADOXA. 131 
21. Roese, C.— “ Beitriige ziu- vergleichenclen Aiiatomie des Herzens 
der Wirbeltiere,’ ‘Morph. Jahrh./ Bd. xvi, 1890. 
22 . Ziegenhageii.— “ Uber die Entwickelung der Cirkulation bei den 
Teleostiern ins besondere bei Belone,” ‘Verb, den anatom. Ges. 
zu Berlin,’ 1896. 
DESCRIPTION OF PLATE 5. 
Illustrating Dr. J. I. Robertson’s Memoir on the ^^Development 
of the Heart and Yascular System of Lepidosiren 
Paradoxa.” 
Reference Letters. 
AA. Third, fourth, fifth and sixth, the four persistent aortic arches. 
A. S. Interanricnlar septum. A. V. p/. Anriculo-ventricnlar ] 3 lug in 
anricnlo-ventricular opening. a. b. c. Three rows of vestigial pocket 
valves, each row having three valves with traces of smaller irregular 
valves between them. B. Ag. Bnlbo-anricular groove. B. C. d. Dis- 
tal segment of bulbns cordis. B.C. p. Proximal segment of bulbus 
cordis. B. C. t. Transverse segment of bulbus cordis. B. E. 3. Left 
longitudinal valve in the distal segment of the bulbus cordis, b. 
Dorsal row of vestigial valves in the jDroximal segment of the bulbus. 
C. V. Cut ends of coronary vein. D. Constriction between B.C.t. and 
B. C.d. L. A. Left auricle. l.D.C. Left ductus cuvieri. P.B. pericardiac 
band. P. Constriction between B. C.t. and B. C.p. Per. Pericardium. 
P. f. Pulmonary fold guarding opening of pulmonary vein. P. V. 
Pulmonary vein. P. V. C. Entrance of the posterior vena cava to the 
sinus venosus. P. A. Right auricle, r. D. C. Right ductus Cuvieri. 
r. S. A. Right sinu-auricular fold ; the arrow indicates the sinu-auricular 
aperture. S. Ao. Prominence of the ventral aortic sei 3 tuni, which is 
formed by the fusion of the left longitudinal and spiral valves in the 
extremely short ventral aorta. S}). V. d. Distal part of spiral valve. 
S}h V. p. Proximal part of spiral valve. Sp. V. t. Transv^erse part 
of the spiral valve. S. V. Sinus venosus. t.f. Transverse furrows at 
the base of the spiral valve showing traces of valvular pocketiugs. 
V. Ventricle. V. B. o. Bulbo-ventricular orifice indicated by arrow- 
head. V. S. Interventricular septum. 
Fig. 1. — Drawing of the adult heart from the right side magnified 
al)out 05 times. The right walls of the right auricle and ventricle and 
of the pioximal part of the bulbus cordis have been removed to show 
