AUGUST 25, 1899.] 
and then examined in the dark. They re- 
mained bright at least half a minute, when 
kept at a low temperature after excitation. 
Calcium tungstate was found to give 
phosphorescence decidedly green in color, 
after being exposed to an are light, while 
at the temperature of liquid air, and then 
examined in the dark. When this sub- 
stance is subjected to the influence of 
Rontgen rays the fluorescence produced 
appears white. 
Experiments on the present subject will 
be continued when more liquefied air is 
procured. 
C. C. TROWBRIDGE. 
PHYSICAL LABORATORY, 
CoLUMBIA UNIVERSITY. 
SCIENTIFIC BOOKS. 
Synopsis of the Recent and Tertiary Leptonacea 
of North America and the West Indies. [Pro- 
ceedings U. S. National Museum, Vol. XXI., 
Pages 873-897 (with Plates LXXXVIL., 
LXXXVIII.) 1899.] By Wriu1Am H. DALL. 
The Mollusca of Funafuti. Part. I., Gastro- 
poda, [Memoirs of Australian Museum III., 
Part 7, March 6, 1899.] By CHARLES HED- 
LEY. 
In the first of these two very interesting and 
valuable additions to the literature of Malacol- 
ogy, Dr. Dall gives descriptions and figures of 
eighteen (18) new species and conveniently ar- 
ranges all the known forms in the three lists 
—Kast Coast, West Coast, and Tertiary—show- 
ing that of the thirty-five east coast species 
enumerated, there are but two (Kellia subor- 
bicularis and Turtonia minuta) which are found 
also on the west coast, the Laswa rubra from 
Bermuda proving to be a distinct species. 
But four (Kellia suborbicularis, Mysella planu- 
lata, Turtonia minuta and Aligena elevata) are 
also found among the fossils. Many interesting 
changes are made in the synonymy, especially 
in the species from northeastern waters, some 
alteration in the name being made in every in- 
stance. They require the careful consideration 
of students interested in these small forms. 
The combining of the recent genus Kelliopsis 
Verrill and Bush (1898) with the fossil genus 
SCIENCE. 
249 
Aligena H. C. Lea (1846) is unquestionably cor- 
rect, but it is not made clear why Abra xquata 
Conrad (1843) (p. 877) is given as the type, and 
the two species (A. striata and A. lxvis) de- 
scribed and figured by Lea fail to be mentioned 
even in the list of Tertiary species. 
It is very doubtful if the combining of the 
genus Mysella Angas (1877) with Montacuta 
Verrill and Bush (1898) (the universally ac- 
cepted interpretation of this genus), and the 
new interpretation of Montacuta Turton (1822), 
should remain unquestioned (p. 881). 
In Mysella the hinge, the most important 
character, is described by Angas as consisting, 
in one valve, of a small, diverging, triangular 
cartilage-pit, close to which is a single, small, 
diverging, subcircular, flattened cardinal tooth ; 
and, in the opposite valve, of two, thin, short, 
horizontal, lateral processes (P. Z.S. London, p. 
176, 1877). The figures given of the only species 
(M. anomala) are entirely too small for accurate 
study and apparently resemble those of M. sub- 
striata as much as those of M. bidentata. It 
would seem improbable, however, that Angas 
could have failed to recognize the relationship 
of the Australian form to either or both of 
these well-known species. Probably with a 
more critical study of the specimen itself and 
with more material new points would be 
brought out, especially as it was placed by 
Angas between Ervilia and Cytherea, well sep- 
arated from Kellia. In the species which Dr. 
Dall refers to Montacuta Turton, he describes 
and figures the hinge as having a prominent 
eardinal in each valve; the lamellz obsolete ; 
sockets for the resilium thickened and raised 
above the inner surface of the valve (MZ. florida- 
num, p. 893). The other species are similar to 
this, but he places the Tellimya ferruginosa Ver- 
rill (non Montagu) = percompressa Dall (p. 894) 
with them. 
Tn an interior view of percompressa, the valves 
united, the dark brown resilium is somewhat 
triangular in form and lies underneath the 
beaks, fastened by its thin, inner edge to the 
sunken sockets which lie underneath the thick- 
ened posterior hinge-margin ; its outer or upper 
edge is thick and broad, and bears an incon- 
spicuous, thin, white ossicle. In one valve the 
anterior hinge-margin is thicker than in the 
