1899] THOSE CRETACEOUS GRYPHAEAS 7 



occur in countless thousands, form extensive masses of indurated strata, 

 the outcrop of which can be traced for many miles ; they are some- 

 times used for road metal, or collected and burned for lime. They 

 have been named and renamed, until their specific identity is hidden 

 under a mountain of literature, and this mountain Messrs. Hill and 

 Vaughan have at last removed. The authors find that certain forms of 

 these Ostreidae possess very distinct specific characters, have definite geolo- 

 gical horizons, and are of the greatest value in stratigraphic work. And 

 this conclusion seems to be quite an usual one when people take the 

 trouble to collect a sufficient number of individuals of any species, and 

 do not content themselves by describing a single specimen or every 

 minute variation as of specific value. 



The Gryphaeas of the Texan Region are now reduced to six species, 

 and of these six the authors give no less than 231 figures, thus affording 

 an excellent opportunity for every one to see the variability among the 

 species. The figures are excellent, and the paper may be recommended 

 as a specimen of what is wanted in palaeontology in this country — 

 namely, a careful and critical study of important types rather than 

 mere descriptions of a jumble of more or less fragmentary and doubtful 

 specimens. 



The San Jose Scale. 



This insect, the source of considerable loss and trouble in the United 

 States, has apparently been localised as an inhabitant of Japan. At 

 least Mr. Cockerell, Mr. Alexander Craw, and Mr. F. M. Webster have 

 by careful search found it several times on trees received direct from 

 that land. The latter of these authors has written a short paper in the 

 Canadian Entomologist for July, in which he asks that a competent 

 entomologist may now be sent to Japan to locate it, and to find the 

 natural enemies of the insect so as to import them into America. As 

 Mr. Webster points out, the expenses connected with such an investiga- 

 tion would be a mere nothing compared with the amount spent in 

 trying to exterminate the scale in those localities in the United States 

 where it has obtained a foothold. 



A Warlike Entomostraean and a Decrepit Trilobite. 



Fkom the Chemung group of New York — that is, from strata of late 

 Devonian age — Mr. John M. Clarke, the well-known palaeontologist, 

 describes and figures a new Phyllocarid crustacean (\Wi Ann. Rep. 

 State Geologist, N.Y.). He names it the bristling shrimp horrent with 

 javelins {Pcphricaris TiorrvpUatd). Each valve is fringed with some 

 two dozen spikes, which make a truly imposing show. There is, how- 

 ever, nothing unusual in the development of striking armature upon 

 crustaceans and their allies. Witness, for example, the headpiece of 

 Hemiaspis horridus, Woodward, the tailpiece in various species of the 



