Mat 17, 1907] 



SCIENCE 



775 



etc. Specimens were shown illustrating 

 the mottled effect which this texture gives 

 to the rock under various conditions, from 

 those of the ' lustermottled melaphyre ' to 

 those of the ' varioloid greenstone.' The 

 origin of the mottling is partly the ready 

 alteration of the olivine, partly the poros- 

 ity between the augite crystals. This latter 

 character may be rather characteristic of 

 the effusives. 



Occurrence of Diamonds in North America : 

 George F. Kunz. Eead by title. 



Silver-gold Ores at San Pedro de Guana- 

 cevi, Durango, Mex.: Frederick B. 

 Peck. No abstract received. 



Perspective View of the Submarine Canyon 

 of the Hudson River: J. W. Spencer. 

 Read by title. (Read before Section E, 

 American Association for the Advance- 

 ment of Science, December 31.) 



Titaniferous Basalts of the Western Medi- 

 terranean. H. S. Washington. Read 

 by title. 



The Paleozoic Section of the Upper Tuhon: 

 A. H. Brooks and B. M. Kindle. Read 

 by title. 



Stratigraphic Siiccession North of Cook In- 

 let, Alaska: Sidney Paige and Adolph 

 Knopf. (Introduced by A. H. Brooks.) 

 Read by title. 



Seismological Observations in the United 

 States: H. F. Reid. Read by title. 



Peale's Painting of the Exhuming of the 

 First American Mastodon: Arthur Bib- 

 bins. Read by title. (Read before Sec- 

 tion B, American Association for the 

 Advancement of Science, December 31.) 



Relatione of the Ithaca and Chemung 

 Faunas of Western Maryland: C. K. 

 SwARTZ. Read by title. 



Edmund Otis Hovbt. 



ZOOLOGY AT TEE NEW YORK MEETINa 



II. 



The Order of Appearance of the Ambu- 



lacral Appendages in Holothima flori- 



dana Pourtales:^ Charles L. Edwards. 



Tentacles.!— D-aTing the fourth day the 

 embryo has a primitive symmetry of four 

 tentacles ; one placed in the mid dorsal in- 

 terradius arising from the left dorsal radial 

 canal, one in the right dorsal interradius 

 from the right ventral radial canal, one in 

 the right ventral interradius from the mid 

 ventral radial canal and one in the left 

 dorsal interradius from the left ventral 

 radial canal. During the fifth and last 

 day within the vitelline membrane, the 

 embryo buds a fifth tentacle into the left 

 ventral interradius from the mid ventral 

 radial canal. In this condition the Holo- 

 thurid hatches during the sixth day but it 

 is not until the eighth day that the fifti 

 tentacle has grown to the size of the four 

 primitive tentacles. On the fortieth day 

 a sixth tentacle develops in the right ven- 

 tral interradius from the right ventral 

 radial canal. From the forty-second to 

 the forty-fifth days the next three ten- 

 tacles appear ; the seventh, in the left ven- 

 tral interradius, from the left ventral 

 radial canal, the eighth, in the mid dorsal 

 interradius from the right dorsal radial 

 canal and the ninth, in either the right or 

 left dorsal interradius, from the right or 

 left dorsal radial canal, respectively. On 

 the fifty-third day the tenth tentacle ap- 

 pears in the dorsal interradius opposite 

 to that in which the ninth has developed. 

 On the seventy-fifth day the eleventh ten- 

 tacle appears in the mid dorsal interradiua. 



Pedicels and Papillce. — The first pedicel 

 has budded from the posterior end of the 



^ Formerly identified as Mulleria agassizii Sel. 

 — Edwards, 0. L., ' Notes on the Embryology of 

 Mulleria Agassikii Sel., a Holothurian common at 

 Green Turtle Cay, Bahamas,' Johns Hopkins Univ. 

 Circ, 1889, Vol. VIII., p. 37. 



