GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 507 



Columellar tangle composed of indefinite, confused processes 

 from the inner ends of the septa among which an axial plate is recog- 

 nizable in a few calices. 



Locality and geologic occurrence. — Canal Zone, station 6016, quar- 

 ry in the Emperador limestone, Empire, collected by T. W. Vaughan 

 and D. F. MacDonald. 



Anguilla, station 6833, Crocus Bay, collected by T. W. Vaughan. 



Gotypes,—No. 325046a, U.S.N.M. (4 specimens.) 



The identification of the specimen represented by plate 152, 

 figures 5, 5a (No. 325046&, U.S.N.M.), is not positive. 



Class HYDROZOA. 



Order HYDROCORALLINAE Moseley. 1 

 Family MILLEPORIDAE L. Aggassiz. 



Genus MILLEPORA Linnaeus. 



MILLEPORA ALCICORNIS Linnaeus. 



1758. Millepora alcicornis Linnaeus, Syst. Nat., ed. 10, p. 791. 

 1898. Millepora alcicornis Hickson, Zool. Soc. London Proc. for 1898, p. 256. 

 1901. Millepora alcicornis Vaughan, U. S. Fish Com. Bull, for 1900, vol 2, p. 318, 

 pis. 35-38. 



Locality and geologic occurrence. — Canal Zone, Pleistocene, stations 

 5850 and 6039, Mount Hope, collected by D. F. MacDonald. One of 

 the two specimens is partly incrusted by Polytrema mineaceum 

 (Linnaeus). Millepora alcicornis is found living on the West Indian 

 and Floridian coral reefs nearly everywhere there are such reefs 

 and in the Bermudas. According to Hickson, there is only one 

 living species, which is Indo-Pacific as well as Atlantic in its distri- 

 bution. 



EXPLANATIONS OF PLATES. 



Plate 68. 



West Indian Shore Lines. p e 



A. Five Islands Harbor, Antigua 273 



B. Spencer Bay, Antigua 273 



C. Publiken Bay, St. Bartholomew 275 



D. St. Jean Bay, St. Bartholomew 275 



Plate 69. 

 West Indian Shore Lines. 



A. Pointe Blanche, St. Martin 276 



B. East side of Crocus Bay, north side of Anguilla 276 



C. Calls Pond, Anguilla 277 



D. Shore, south side of Anguilla, looking toward St. Martin 276 



1 These organisms are not corals, but, as they are usually associated with corals and contribute calcium 

 carbonate to reefs, accounts of them are frequently included in discussion of Madreporia. 



