MONOGRAPH 



OF THE EECENT SPECIES OE THE GENUS 



SOLABIUM of Lamarck. 



By SYLVANUS HANLEY, B.A., F.L.S., etc. 



Char. Gen. More or less conoidal or disciform, with a large 

 umbilical cavity, which, for the most part, is deuticulately crenated 

 within; periphery more or less angular in general; mouth never 

 pearly ; operculum horny ; spiral, oval, or circular. 



Section A. {Architectoniea, Bolten.) — Periphery angular ; 

 mouth rhombic ; whorls belted above, usually with radiating 

 sculpture ; inner lip straight, or nearly so, with a single canalicu- 

 lated notch at the termination of the umbilical cord, which latter 

 is always creno-dentated; umbilicus never ribbed spirally ; oper- 

 culum suboval, flattened, quickly spiral at one end ; internal 

 nucleus circular-based, composed of very numerous erect scales. 



Section B. [Philippia, Gray.) — Shell as in the last, but the 

 whorls not belted posteriorly, and devoid of radiating sculpture ; 

 operculum circular-based, multispiral, concave externally, inter- 

 nally with a small abrupt central mammillary apex. 



Section C. [Torinia, Gray.) — Surface corded throughout; peri- 

 phery bluntly biangulated or even rounded, more rarely angular; 

 mouth more frequently suborbicular ; umbilicus in the typical 

 species relatively narrow, and encircled by one or more spiral 

 ridges; operculum circular-based, multispiral, composed of nu- 

 merous membranaceous layers, either forming a peak or truncated. 



My aim in adopting these sections is to enable the conchologists 

 of both the Lamarckian, and the more modern English school, to 

 arrange their cabinets according to their several predilections. 



