Holland: Heads and Tails. 277 



admit that our specimen is so far forth defective. We cannot by any 

 possibility, for physical reasons, attribute to it the skull, which we 

 possess, and which is like that employed by Professor Marsh, because 

 it was found in a higher layer, further up stream, associated with the 

 remains of so-called Barosaiirns. 



The problem is naturally perplexing, and in certain aspects amusing. 

 My good friend, Dr. Osborn, has in a bantering mood "dared" me to 

 mount the head, which we have found associated with our Bronto- 

 saiints, on the atlas, which it fits. At moments I am inclined to take 

 his "dare," in spite of Professor Marsh's action, being not trained 

 unquestioningly to accept the ipse dixit of even so learned an authority 

 as Professor Marsh was. I feel that there is quite as much reason for 

 putting this kind of a head on the animal as for topping off the beast 

 with the style of headgear which Professor Marsh has associated with 

 it. So much for heads. 



And now as to tails. One of the most interesting results of the 

 excavations made by us, has been the discovery of the fact that in 

 at least three cases the reptiles which we have exhumed have pre- 

 served in place the so-called "whip-lash," which we know to have 

 characterized Diplodociis. The large skeleton of Brontosaurus, 

 which we are setting up, has a tail relatively as long as that of Diplod- 

 ociis, and the posterior vertebrae of the tail were found in a more or 

 less continuous series in such a position as not to admit of any doubt 

 that they belonged to the same individual. A second skeleton of a 

 smaller dinosaur, also related to Brontosaurus, but probably belonging 

 to a genus which may not as yet have been defined, likewise has a 

 very long tail, in which the posterior caudals were found articulated 

 one with another, as was the case with the one provisionally referred 

 to Brontosaurus. A still more remarkable specimen was found em- 

 bedded in a layer of fine white sand at the western end of the quarry, 

 all the vertebrae from the atlas to the tip of the tail being in situ. 

 There are in this specimen eighty-two caudal vertebrae. A lantern 

 slide which I am herewith communicating to the meeting (Plate LIX) 

 shows the terminal caudals from thirty-four to eighty-two, inclusive,, 

 arranged in order. This "whip-lash," as it has been styled, recalls 

 the long tail of the Monitors, and must have been a weapon of defence 

 in the case of these colossal reptilia, as it is in the case of the Monitors. 

 My friend and associate, Dr. L. E. Grififin, long connected with the 

 Bureau of Science in the Philippines, informs me that for some time 



