104 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



that Owen had but a single .specimen for dissection and no guides in his work, we can not but 

 recognize the patient genius which enabled him to produce so complete, clear, accurate, and 

 enduring a work. 



The work of Valenciennes (1841) added to our knowledge minor facts which Owen had not 

 described, beside correcting Owen in a few .-light errors. 



Both these anatomists had female specimens. Van dek Hoeven (1848, L856)was the first to 

 dissect and describe a male Nautilus. 



Between then and now numerous papers have appeared treating of various points in the 

 anatomy of Nautilus. But still its development is entirely unknown. Only recently Willet 

 has spent a considerable time in New Guinea in the endeavor to obtain its embryology. He has 

 published a number of interesting papers upon details of its anatomy and its habits, and has 

 succeeded in obtaining fertilized eggs, but has so far kept silence regarding their development. 



Such a paper as my own may seem superfluous to many in view of the numerous papers 

 which have already been published upon the same subject. But I hope that it will have a useful 

 place since I have endeavored to gather together the various disconnected accounts of Nautilus 

 anatomy and, adding to them what new facts I lane been able to discover, to publish an account 

 of the gross anatomy of Nautilus which shall be as complete as possible. Few persons have the 

 opportunity, and still fewer the time to examine all the various papers on this subject, so I hope 

 that, beside adding to our knowledge of Nautilus, this paper may be found convenient by the 

 student of comparative anatomy. 



Although the shell of the animal might properly be considered in an anatomical description, 

 in this case it is so well known that another description of it by me would serve no good purpose. 



The Nautili of the Menage collection were captured in water of 1,800 feet depth off the south- 

 ern coast of Negros, Philippine Islands. An extract from a letter of Professor Worcester to 

 the Minnesota Academy of Natural Sciences tells of the mode of capturing the animals. 



'"Their (the natives') method is to lower a large bamboo basket, baited with meat, in six or 

 eight hundred feet of water. This basket is made on the principle of the old-fashioned rat trap, 

 allowing the animal to enter easily but preventing its escape. Every morning these traps arc 

 drawn up for inspection, and a single one sometimes contains four or five live Pearly Nautili: 

 which are sold for food, bringing about 4 cents apiece." 



This was written after a preliminary examination of the ground, but several months before 

 the capture of the specimens which were sent to this country. The specimens taken by the 

 expedition were caught in deeper water than that mentioned in the letter. 



The natives ordinarily set their traps for a deep-sea food fish, the capture of the Nautili 

 being in a measure accidental, at most, incidental. 



Nautilus is not confined to deep water. It has generally been found there, but Willet has 

 also obtained it in water only '2 or ?> fathoms in depth. 



Nautilus is carnivorous, and apparently predatory, the crop and stomach of captured 

 specimens being usually filled with fragments of Crustacea, or the chicken, or fish, or whatever 

 other meat is used for baiting the trap. The appearances indicate that it feeds mostly upon a 

 species of decapod Crustacea. These are devoured shell and all. The jaws appear strong 

 enough to crush any moderately thick-shelled mollusk upon which the Nautilus might happen. 



Willet (1897,1) says: "One of the surest ways of obtaining Nautilus, and in fact, the 

 method by which I have obtained most of my specimens at Lifu. is to bait the fish basket with 

 the cooked and bruised exoskeleton of Palinurus, or an allied form. The strongly scented 

 ■potage' so produced is then wrapped up in cocoanut fibre like a small parcel, and then placed in 

 the fish trap overnight. There is therefore nothing to be seen, but on the other hand there is 

 something to be smelt, and by this means I have obtained as many as ten Nautili at one time." 



While this observation points to the probability of Nautilus being chiefly guided by its sense 

 of smell in the capture of its prey, it is not by any means proof that the eyes are not also use fill 

 in this action. We would rather expect tiiat smell would lie the guiding sense from the fact 

 that the Nautilus is usually found at great depths where darkness must prevail, and from the 

 simple character of the eyes. 



