170 MEMOIRS OF THE CARNEGIE MUSEUM 



water. The head is drawn back and then thrust forward like a spear, with wonder- 

 ful rapidity and precision the prey being transfixed on the closed, lance-like 

 mandibles. When prepared to deliver the blow, the angle formed by the seventh 

 and vertebrae points backwards, and the one between the eighth and ninth forwards, 

 the eighth vertebra itself standing subvertically between them. Gannets and 

 Herons have the same arrangement of these cervical vertebrae, but nothing like as 

 well developed as we find it in the Darters. Bitterns show it well, 11 as do all our 

 American Herons, and they transfix their prey, although they do not pursue it 

 under water as the Darters habitually do. 



P. urile has handsomely developed parapophysial spines on its cervical verte- 

 brae. They are rudimentary on the atlas and axis, coming to be of good size on the 

 third vertebra. From it on they gradually increase in length, but diminish in 

 caliber, until we come to the tenth cervical. In it they are as straight as sewing 

 needles, and as long as the centrum of the vertebra. They die out on the fifteenth 

 cervical. The lateral canals are normally developed and of good size in the third 

 vertebra at its anterior part. They very gradually increase in size down the series, 

 until we arrive at the first vertebra bearing free ribs. On the other hand the hypa- 

 pophysial carotid canal begins in the fourteenth vertebra, and terminates in the 

 seventh ; it never quite closes in so as to form a perfect tube, but comes very near it 

 in the thirteenth vertebra. A large haemal spine suddenly appears on the fifteenth 

 cervical, and the character persists down the series, to include the leading two or 

 three vertebrae of the pelvic sacrum. Haemal spines are also found on the atlas and 

 axis ; and a strong neural spine first appears on the sixteenth vertebra, while on 

 the eighteenth to the twenty-third inclusive they are very large, strong, oblong in 

 form, and much in contact with each other in the dorsal region of the spine ; the 

 various articulations among the vertebrae, are very close indeed. Here the centra 

 are much compressed from side to side ; the transverse processes narrow and spread- 

 ing, and these latter have strong metapophysial spinesinterlocking at their extremities. 

 But there is none of that luxuriant interlacing of ossified tendons that we see 

 there, and on the neural spines and anterior iliac margins, as in Anhinga. Phala- 

 crocorax is more or less free from that. 



There are three pairs of large, strong dorsal ribs, bearing great, flat, anchylosed 

 unciform appendages. By a graduated series of costal ribs, these vertebral ribs join 

 with the sternum. The first pair of pelvic ribs likewise, by a very long pair of 

 hsemapophyses, connect with the sternum. Small unciform processes also appear 

 upon them, but not on the last pair of pelvic ribs that follow these. Nor do the 



11 See the author's reference to this in the American Bittern in The Auk, Vol. X., No. 1, January, 1893, pp. 77-78. 



