876 Report or tHE STATE GEOLOGIST. 
Type, Liothyrina vitrea, Born (sp.). 
Distribution. Tertiary — Recent (Arctic, Lusitanian, West 
African, Indo-Pacific, Australo-Zealandian, Japanese, Californian, 
Panamic, Peruvian, Magellanian, Patagonian and Caribbean 
Provinces). 
Eucalathis, Fischer and (hlert. 1890. 
Shell small, auriculate; valves convex, covered with radiating 
plications. In the interior are neither dental plates nor septa. 
Cardinal process distinct. Loop short; descending branches 
with oral processes distinct, and directly in front of them 
the lamella are deflected into a transverse band which 
Fias. 532, 583. EHucalathis Murrayi, Davidson (sp.). (Davmpson.) 
bears a narrow median fold. Brachia but slightly dev- 
eloped, scarcely longer than the loop and arranged in two 
lobes. 
Type, Zucalathis Murray, Davidson (sp.). 
Distribution. Recent (Lusitanian Province). 
Dyscolia, Fischer and Ghlert. 1890. 
Shells of large size, subtrigonal, faintly auriculate; valves con- 
vex with radiating surface stria. Beak short, foramen large, 
deltarium concave, transversely striated, much thickened in old 
shells. On the interior neither septum nor dental plates. In the 
brachial valve there is no hinge plate. Loop broad and short, 
descending processes united anteriorly by a transverse band as in 
Liornyxina. Brachia represented by a subrectangular brachial 
128 
