97 
Fam. Syntrophild^e. 
Genus Huenella, Walcott. 
Huenella divaricata, Chapman sp. Plate VI., fig. 14. 
Orthis ( Bilobites ) divaricata , Chapman, 1904, Rec. Geol. Surv. Viet., vol. I., 
pt. 3, p. 224, pi. XXL, fig. 9. 
Observations. —-This shell appears to be a numerously costate form of the 
Cambrian genus, Huenella. The number of plicae is doubled at half the 
distance to the anterior margin by the interposition of secondary riblets. 
The type specimen, figured in 1904, represents a ventral valve, whilst that now 
shown is a dorsal valve. 
Relationships. —The above species shows some affinity to Huenella lesleyi, 
Walcott 2 , from the Upper Cambrian of Utah, but it has a shorter cardinal 
line and more pronounced divaricate costation. 
Fam. Clitambonitid^e. 
Genus Clitambonites, Pander. 
Clitambonites flabelloides, Chapman sp. Plate VI., figs. 15-17. 
Strophomena flabelloides, Chapman, 1904, Rec. Geol. Surv. Viet., vol. I., 
pt. 3, p. 223, pi. XXI., fig. 5. 
Emended description. —Shell quadrate, with a straight cardinal line and 
sloping, rounded, or subangulate margin. Cardinal area high. Spondylium 
large, often occupying half the length of the ventral valve. External surface 
deeply plicate, with a variable number of folds, sometimes eighteen, according 
to the development of secondary riblets between the major folds of the shell. 
Dimensions. —Type specimen, length and width, 5'6 mm. Other 
examples : length, 4 mm. ; width, 8T6 mm. (probably distorted) ; and 
length, 6 • 33 mm. ; width, 6 * 66 mm. 
Observations.-— None of the hitherto described forms of Clitambonites show 
so strong a plication, and it may therefore be necessary to institute a new 
genus for these forerunners of the Lower Ordovician fossils. 
Class PELECYPODA. 
Fam. GRAMMYSIIDyE. 
Genus Grammysia, Verneuil. 
(?)Grammysia heathcotiensis, sp. nov. Plate VI., fig. 18. 
Description. —-Shell elongate ovate ; highest in the anterior third ; length 
more than three times the height. Umbo not prominent, but convexly 
rounded. Specimen broken in front, but probably with a rounded border 
tapering posteriorly, with extremity acute. Umbonal sulcus distinct, as a 
shallow oblique fold, which sinuates the ventral margin of the shell. 
Ornament consisting of four or five undulating low ridges which ventrally 
appear to interdigitate. 
Dimensions. —Length, circ., 16 mm. ; height, 5 mm. 
3 Smithsonian Misc. Colls., vol LIII., 1908, No. 1810, p. 110, pi. X., figs 12, 12a. 
6318.—4 
