Valve elliptical, with distinct, interrupted, pruinose, irregular markings diverging in curved lines toward the circumference in the median part and converging toward the processes, interspersed with numerous darker markings having the appearance of apiculi. Central space nearly circular, sometimes with several granules. Processes large near the ends of the major axis and not oblique to it, or scarcely so, the edges with a crenulate border. Blue clay. Rather rare. Pl. 5, Fig. 8. {29}AULISCUS SCULPTUS (WM. SM.) RALFS Valve elliptical or subcircular, median areas distinct, rounded, circumscribed by coarse distant costæ radiating near the border where they are more evident, and converging toward the processes. Central space rounded, sometimes indefinite. Processes, two, circular. Typical specimens show wide, coarse, distant costæ, but, in some cases, the median areas are indistinctly outlined. Blue clay. Pl. 5, Fig. 5. AULISCUS CÆLATUS BAIL. Valve elliptical or subcircular, with radiating costæ, more evident around the median areas and at the border, converging toward the processes, with intermediate punctate radiating lines. Central space rounded or irregular. Processes circular. A. sculptus has coarser costæ and the interspaces are hyaline, or apparently so, while in A. cælatus the punctate striæ between the costæ are more evident. Blue clay. Not uncommon. Pl. 5, Fig. 4. Fig. 7 is a small, indefinite form intermediate between A. sculptus and A. cælatus. The numerous variations in this genus make it difficult to satisfactorily differentiate the species. The size of the four above described varies from 40 to 150 µ. PSEUDAULISCUS A. S. (1875) AND LEUDUGER-FORTMOREL (1879) Valve circular or subcircular, nearly flat or depressed at the centre. Central space not evident. Processes circular, with narrow border, near the circumference. Border narrow, striated. Markings granular, radiating, sometimes interspersed with striæ and apiculi. Differs from Auliscus chiefly in the absence of a central space and costæ. PSEUDAULISCUS RADIATUS (BAIL.) RATTR. Valve circular, or nearly so, flat. Central area with scattered granules radiating and increasing in size outward in diverging rows toward the border which is coarsely striated. Processes, two, circular. Two small apiculi are inserted at about one-fifth the radius from the border near the ends of the minor axis. Blue clay. Rare. Pl. 5, Fig. 9. The apiculi are not always figured. They appear in a number of specimens from the Miocene of Maryland, Atlantic City, Harvey Cedars and Newbern. PSEUDAULISCUS SPINOSUS (CHRISTIAN) RATTR.