472 Transactions. 
to its fragility. The type is the only perfect and double-valved specimen 
so far obtained. 
Genus and species new to fauna, though it is a very widely spread genus, 
and three fossil members have already been described from Australia. Of 
these, S. legrandi Tate is very close to the new species, presenting the same 
type of grooving and differing in only a few details. Tate gives its dimen- 
sions as “ Height, 40 mm. ; width, 17:5 mm."—a ratio of 2-29:1 : but his 
figure measures 40-5 x 16-75—a ratio of 2-429 : 1. The ratio in S. bensoni 
is 2-95 : 1, so that this species is relatively longer than S. legrandi, which 
seems to differ also in the absence of ventral incurvation, less prominent 
umbos, inconstant height (greater posteriorly), recurved posterior dorsal 
margin, and slightly different slope of sculpture-lines, which dorsally are 
not initially subparallel to margin, and ventrally do not reverse in direction 
on posterior end. From 8. dennanti Tate and 8. ellipticus Tate the new 
species is easily distinguished by the character of grooves, This elegant 
New Zealand species is with much pleasure dedicated to Dr. W. N. Benson, 
friend and former teacher of the writer. ; 
Solecurtus evolutus n. sp. (Plate 50, fig. 9.) 
Evidently a direct descendant of the previous ene, occurring at the 
same locality in beds geologically a little younger. It agrees with it in all 
main features, but is slightly more solid, decidedly shorter (especially the 
posterior end), and higher, with slightly less numerous but stronger and 
more conspicuous grooves. n anterior end grooves cease with one or 
two much shorter but not closer grooves, instead of, as in S. bensoni, several 
long grooves close together. The species seems also less flattened medially. 
"The best-preserved specimen, chosen as holotype, is still considerably - 
fractured, so that its dimensions are somewhat hypothetical: its greatest 
length is 31-5 mm., greatest height 15-5 mm., and greatest width (one valve) 
. И one measures from the largest perfectly intact growth-line the 
dimensions are 22 mm., 10 mm. mm 
The present species has the ratio length : height a little over 2-2 : 1, and 
this brings it even closer than the previous species to S. legrandi Tate. The 
authors thanks are due to Mr. Chapman, of the National Museum, Mel- 
bourne, for comparing a photograph of the type and some fragments of 
the shell with the type of Tate’s species; he agrees with the author that 
the two forms are distinct, though very closely related. 
Solecurtus chattonensis n. Sp. (Plate 50, fig. 10.) 
At once distinguished from the two preceding species by its proportions 
and the different character of | grooves. Anterior side relatively much 
regard to height than S. evolutus. The grooves are only half as numerous 
and have a different disposition: there are only 17 grooves altogether 
о 
їп {һе type, while S. bensoni of similar size has about 35 and adult shells 
