January 31, 1913] 



SCIENCE 



191 



fore the numerous questions raised by our 

 feeding trials can be regarded as settled, and 

 attention must finally be given to the relative 

 food value of mixtures of various food stuffs 

 with corn meal, so that we may know as defi- 

 nitely as possible the most economical combi- 

 nations to employ in maintaining mature ani- 

 mals and in raising the young. Such experi- 

 ments must be conducted on a large scale and 

 with a variety of domestic animals. In carry- 

 ing these out the results obtained by the 

 method I have just described when combined 

 with the experience gained in feeding animals 

 for market will doubtless lead to a lower cost 

 of meat production, and at the same time give 

 us information which will contribute to a 

 clearer understanding of some of the obscure 

 problems of the chemical physiology of nutri- 

 tion. Thomas B. Osborne 

 Connecticut Agricultural 

 Experiment Station, 

 New Haven, Conn. 



DISCOVERY OF bivalve CRUSTACEA IN THE COAL 

 MEASURES NEAR PAWTUCKET, R. I. 



While collecting fossils for the Museum of 

 Comparative Zoology, Cambridge, from the 

 Carboniferous graphitic slates of Central Falls, 

 Ehode Island, last June, the writer discovered 

 in a haK inch layer at two localities one hun- 

 dred yards apart about two dozen, more or less 

 well preserved impressions of carapaces of 

 bivalve Crustacea of the genera Leaia and 

 Estheria, in the same layer with numerous 

 plant impressions, chiefly leaves of Cordaites 

 and Calamites. No record of their having been 

 previously discovered in the Narragansett 

 Basin Coal Measures was found by the writer, 

 and no specimens of any bivalve Crustacea 

 occur in the collection of Coal Measure mater- 

 ial from the basin, at Brown University or 

 at Harvard. 



The faunal remains from the Narragan- 

 sett Basin Coal Measures are comparatively 

 meager, and consist largely of tracks which 

 are in many cases of doubtful determination. 

 Previous to the year 1900, fourteen species of 

 insects and one arachnid were identified by 

 Seudder,' and the tracks of a probable annelid 

 and of a mollusc or worm were described.^ 

 In 1900 A. S. Packard' described some prob- 



able worm tracks, and those of a possible 

 crustacean which were found in some red 

 shale boulders at South Attleboro. He de- 

 scribed and named another track found in a 

 pebble of arenaceous shale in a kame in North 

 Providence, and three fragments of a possible 

 macrurous crustacean from the black shales 

 of Valley Falls, E. I., and noted a locality 

 near East Attleboro, shown to him by Pro- 

 fessor J. B. Woodworth, where sand-filled 

 worm borings occur in the red and green 

 shales. He also described and identified sev- 

 eral casts of valves of a fresh-water mollusc 

 Anthracomya arenacea (Dawson) Hind, from 

 a boulder of fine black shale at Valley Falls, 

 and one specimen from a shale bed north of 

 Silver Spring, East Providence. 



Numerous supposed amphibian tracks have 

 been found by Professor J. B. Woodworth 

 near Plainville, Mass., and one species, Ba- 

 trachichnus plainvillensis, has been described * 

 and named by him. Since then he and the 

 writer have found many types of tracks from 

 several localities near Plainville, and these 

 will probably be described in detail soon. Two 

 or three tracks of probable amphibia were 

 found by Professor Woodworth and the writer 

 last June at Valley Falls and Central Falls, 

 E. I., which is very much south of the locali- 

 ties where they have been previously noted. 



From this brief summary of the occurrence 

 of the fossil fauna, it will be seen that only a 

 part of the specimens have been found in situ, 

 and the majority of these are tracks. The 

 discovery of these bivalve Crustacea in place 

 is therefore of considerable importance. 



The impressions of the valves of Leaia and 

 'Estheria occur in a grayish black, somewhat 

 graphitic slate bed along the south bank of 

 the Blackstone Eiver in Central Falls, E. I. 

 The beds strike N. YO^-SO" E. about parallel 

 with the river at this place, and dip 70° N. 



^BuU. U. S. Geol. Survey, No. 101, 1893. 



""Froc. Bost. Soc. Nat. Hist., XXIV., 1889, pp. 

 209-216, and Amer. Jour. Sci., 3d Ser., XXXVII., 

 1889, p. 411. 



* Amer. Acad. Arts and Sci. Proc, Vol. XXXV., 

 1900, pp. 399-405. 



^Geol. Soc. Am. Bull., Vol. IX., 1900, pp. 449- 

 454. 



