RECORDS OF MEETINGS 439 



sought after so carefully by the natives of Haiti for its delicate flesh that 

 it had already become extremely rare as early as 1836. And no specimen 

 has since reached any natural history museum. Isolohodon has probably 

 been extinct for a few hundred years. 



Dr. Matthew said in abstract : A number of specimens of fossil verte- 

 brates were secured by Dr. Chester A. Eeeds on the Xatural History 

 Survey of Porto Eico under the auspices of the New York Academy of 

 Sciences. Among these is the lower jaw of a Sirenian associated with 

 two vertebras from marine Tertiary limestones of uncertain horizon. 

 The jaw is referred to the genus Halitherium of the European Oligocene 

 and Miocene and represents a new species, H. aiitiUense, nearest to H. 

 Christ oH. 



Halitlieriioi) is a primitive stage of the dugong family (Halicorida?), 

 now found only in the Indian Ocean and Eed Sea, but abundant around 

 the shores of Tertiary Europe. It has never before been reported from 

 this side of the Atlantic. The other family of Sirenians, Manatees, occur 

 on both sides of the Atlantic, but not in the Indian or Pacific oceans, 

 and are now limited to the tropics. The distribution of the dugongs 

 was therefore wider than has been supposed, extending to both sides of 

 the Atlantic as well as to the eastern seas, where they still survive. 



The anterior grinding teeth (premolars) in the dugong series are pro- 

 gressively reduced ; in the manatees they become molariform. The molar 

 premolar formula is briefly considered. The writer accepts AbeFs view 

 that there are but three true molars in the Sirenians and not more than 

 four premolars. The last milk molar is retained very late and sometimes 

 intercalated between p^ and m^. 



Dr. Eastman presented in abstract an account of the more important 

 results of investigation of a large series of Paleozoic fish remains belong- 

 ing to the American Museum, the U. S. National Museum, and otiier 

 institutions, the work having been in progress for over a year. 



Ordovician fish remains from a newly discovered locality in Colorado 

 were described, and the systematic position of one of the oldest known 

 Ostracoderms, Astros pis Walcott, was sho^^m, in the light of unusually 

 well-preserved specimens, to be representative of a distinct family allied 

 to the Psammosteida\ The large dorso-median plate of Asfraspis is of 

 compound nature, being formed of fused tuberculated tesserae. A similar 

 tesselated structure has been observed in Cephalaspids and Psammosteids, 

 and more recently in specimens from Dorpat, Eussia, described by Preo- 

 brajensky in 1910 under the name of DyptycJiosfeus tesselatiis. Another 

 specimen in the Dorpat Museum described by the last-named author as 

 a new species of Psammosteus (P. imperfectvs) appears to be truly refer- 



