The Anatomy of Chlamydoselachus 



In 1889 Ayers, in a work entitled "The Morphology of the Carotids," described the 

 branchial and carotid arteries in Chlamydoselachus, and these arteries, as described by him, 

 were in certain respects quite unusual. Ayers himself called especial attention to this fact, 

 and on the conditions, as described by him, he based certain quite important conclusions. 

 In 1908 I had occasion to consult this work by Ayers, and I then published (AUis, 1908) a 

 diagrammatic representation of the carotid and related arteries in this fish, as described by 

 Ayers but as interpreted by myself. The diagram was, however, most unsatisfactory, and 



467 



am p-cer e/: epsb 



amd 



Text-figure 111. 

 Branchial, pseudobranchial and carotid arteries of Wtptandtw-s cmtrtxxs. 



aal, 11, etc., afferent arteries in the 1st, 2nd etc. branchial arches; acer., anterior cerebral artery; 

 ahy, afferent hyoidean artery; amd, afferent mandibular artery; apsh, afferent pseudobranchial 

 artery; cor, coronary artery; da, dorsal aorta; ea.I.II. etc., efferent arteries in the 1st, 2nd, etc. 

 branchial arches; ec, external carotid; ehy, efferent hyoidean artery; epsh, efferent pseudo- 

 branchial artery; ic, internal carotid; il/i, internal lateral hypobranchial artery; Ida, lateral dorsal 

 aorta; om, ophthalmica magna artery; op, optic artery; peer, posterior cerebral artery; psb, 

 pseudobranch; ta, truncus arteriosus. 

 After AUis, 1912, Fig. 1. 



having since received several heads of this fish, most kindly sent me by Prof. Bashford Dean, 

 I have had dissections made of the arteries concerned, in two of them, the dissections being 

 prepared by my assistant, Mr. Jujiro Nomura. The arteries, as I find them, are shown in 

 the accompanying Figure 1 [my Text-figure 110]. ... 



The arteries in Chlamydoselachus . . . differ in no important particular from those in the 

 Scylhidae and in Mustelus (AUis, 1908), excepting in that the dorsal end of the efferent 

 hyoidean artery has, in Chlamydoselachus, a double connection with the lateral dorsal aorta. 



In Chlamydoselachus, as in elasmobranchs generally, the efFerent'CoUector arteries 

 (Text-figure 110) form complete loops around each gill'cleft excepting the last one. To be 



