458 Bashford Dean tAemorial Volume 



Departing considerably from the conventional form of heart, this genus presents a shape 

 that is somewhat pecuHar. Seen from below, it has a small subquadrangular ventricle, 

 a large auricle, and a long bulbus arteriosus. The ventricle measures nearly three-quarters 

 of an inch in either width or length. When fiUed, the auricle is subtriangular, and measures 

 on each side an inch and a half. The bulbus is almost twice as long as the ventricle. Behind 

 the auricle,and above and behind the ventricle, hes the sinus, w^hich has a capacity that nearly 



Text-figure 101. 



Heart of Chlamydoselachus : A, in ventral view; B, longitudinal section showing cavity 



in ventricle, also valves of the bulbus (conus) arteriosus. 

 1, auricle (atrium); 2, ventricle; 3, bulbus (conus) arteriosus; 4, sinus venosus; J, dark tissue between cardiac 



and abdominal chambers; 6, cavity in ventricle; 7, valves in bulbus (conus). 

 Printed from original wood-cuts after drawings by Paulus Roetter for Garman, 1885.2, Pis. XVII and XVUI. 



equals the bulk of the ventricle. From it the opening into the auricle is guarded by a pair of 

 \'alves that are without chordae. The auriculo-ventricular opening is furnished w^ith a pair of 

 valves provided with chordae tendineae. In the ventricle the cavity or chamber is small; its 

 outhnes in longitudinal section resemble those of a pipe with a short stem, the stem being 

 directed toward the left upper side and the bowl toward the bulbus. Along the inside of 

 the passage (Fig. B, pi. XVIII) [my Text-figure 101b], the muscles he in bands (columnae) 



