. The Bashford Dean memorial volume :. Fishes; Sharks; Fishes, Fossil. The Anatomy of Chlamydoselachus 461 are four transverse rows with at least three valves in each row—the precise number is uncertain. The same may be said of No. I. As stated by Garman (), generally among sharks the conus is shorter and the transverse rows of valves less numerous, than in Chlamydoselachus. In Carman's Pis. 56 and 57 (1913) we find illustrated (without text) the external form of the heart, and the form and arrangement of the valves of the conus arteriosus, in many different species of elasmobranch
. The Bashford Dean memorial volume :. Fishes; Sharks; Fishes, Fossil. The Anatomy of Chlamydoselachus 461 are four transverse rows with at least three valves in each row—the precise number is uncertain. The same may be said of No. I. As stated by Garman (), generally among sharks the conus is shorter and the transverse rows of valves less numerous, than in Chlamydoselachus. In Carman's Pis. 56 and 57 (1913) we find illustrated (without text) the external form of the heart, and the form and arrangement of the valves of the conus arteriosus, in many different species of elasmobranchs. The heart of Heptanchus maculatus (Text-figure 104a) has a fairly long conus arteriosus—longer than that of Hep- hy af., tranchias {Heptanchus) perlo (Garman, 1913, Fig. 1, pi. 56) but shorter than that of Chlamy- doselachus. In Heptanchus (Text'figure 104b) the valves of the conus arteriosus show partial suppression of the second row counting from the distal end of the conus, and complete suppression of the third row. THE BLOOD VESSELS For descriptions of the blood vessels of Chlamydoselachus, we must rely almost entirely on the work of Ayers (1889) and Allis (1908,1911, 1912 and 1923). In several respects, the condition of the arteries as described and portrayed by Ayers is not typical for Chlamydoselachus. His work has been severely criticised, but in view of the marked variability that has been found in other organs and parts of Chlamydoselachus, it seems possible that he worked on an anomalous specimen. I have included two of his figures (Text'figures 105 and 106), because of their his- torical importance and because they are more comprehensive than those of other Text-figure 104. Ventral views of (A) heart and ventral aorta, (B) valves of the conus arteriosus, in Heptanchus maculatus. dp., aperture of last afferent artery; au., auricle (atrium); , first to sixth afferent branchial arteries; , conus arteriosus; , left coronary artery; hy.
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