The T^atural History of the Frilled Shar\ 297 



ture a fulcrum on which to straighten its body in striking forward to sei2;e its prey. This 

 was first suggested by Garman. In ordinary swimming, right and left strokes of the caudal 

 will send the body forward with the sinuous motion common to all slender fishes, 



FOOD OF CHLAMTDOSELACHUS 



Comment has already been made that the large mouth with its distensible jaws fits 

 Chlaynydoselachus for taking in animals of a diameter approximating its own. The large 

 and equally distensible gullet would offer no particular resistance to the backward passage 

 of such large prey. The three-cusped backwardly hooked brier'like teeth would make 

 escape impossible for any soft-bodied animal impaled thereon. Indeed they make difficult 

 the work of exploring the mouth and counting the teeth, as we can affirm. Any handling 

 of the mouth is sure to result in many painful pricks and scratches. 



After studying these structures, Garman well remarks (1884.1, p. 55) that they"leave 

 little room for doubt that the food of the creature was such as possessed comparatively 

 little hardness in the way of mail or other armature." Garman's first specimen was 

 partially eviscerated, the stomach and major part of the intestine being gone, and so 

 he could not make any observations on the food of the fish. He did not dissect his second 

 fish. Giinther dissected the stomach and intestine of at least one of his specimens, but 

 these organs were empty. CoUett (1897-1) certainly dissected his huge specimen, for he 

 states that the stomach was empty. Apparently no one else made such dissections, until 

 Mrs. Hawkes published her investigations in 1907- But as she gives no notes on food, it 

 would seem that her specimen also was empty of food remains. Mertens (1921, p. 176) 

 was the next investigator to dissect the alimentary canal of the frilled shark, also with nega' 

 tive results so far as food contents are concerned. He expressly states that the entire 

 canal was empty. Last of all, Deinega (1925) studied the visceral anatomy. His text is in 

 Russian, but his English resume refers only to structure, and we doubt if there is any indi' 

 cation of the character of the food. 



We have opened the stomachs and intestines of our three adult sharks hoping to find 

 undigested fragments which would indicate the nature of the food of this fish. In the 

 stomach, small and large intestines of No. I there were, aside from some parasites described 

 in the next section, only small quantities of finely divided flocculent brownish material 

 which we were unable to identify under the microscope. In No. II the stomach and small 

 intestine were empty, and in the spiral gut there was only a very small amount of finely 

 divided material which likewise defied microscopical analysis. In No. Ill the stomach was 

 empty, and the finely divided material in small intestine and spiral gut contained nothing 

 recogniziable as organic matter. Doctor White's specimen was eviscerated before it came 

 into her hands, so no information about the food can be had from it. 



We have stated elsewhere from Dean's notes that, occasionally at least, squid were 

 used as bait in fishing for Chlamydoselachus, and that some specimens were caught by 

 the use of this bait. Presumably, squid form part of the natural food of the fish. 



