40 Eevieics — Br. G. Lindstrmn^ s Silurian Gadcropoda, etc. 



Enomphalopteriis, F. Roeraer, and Gosselefia, Agnesta, Lnciella and 

 Mourlonia, De Koninck. Remarking on the absence of any satisfac- 

 tory distinction between Murchisonia and Fleurotomaria, Lindstroni 

 proposes that the forms with elongated slender spires of more than 

 six bead-like whorls, should be retained under the former genus. 

 The numerous species of Fleurotomaria are ranged in eight sub- 

 divisions, mainly based on the characters of the slit-band. Some of 

 the Gotland shells yet retain their inner nacreous layer and the 

 minutest details of their surface-ornamentation. 



It appears that the well-known Silurian species Euomphalus 

 carinatus, Sow., possesses a distinct slit band and therefore must be 

 removed to Fleurotomaria, and as its specific name is already pre- 

 occupied, the author proposes to give it the name P. limata. For a 

 similar reason Euomphalus alalus, Wahl., is also placed in Fleuroto- 

 maria. 



In the family of the Euomphalidse are included Euomplialus and 

 Loxonema, and five species of each of these genera are described. 

 The author restricts Euomphalus, Sow., to the forms, such as E. 

 pentavgulatus, which were first placed in it by Sowerby. 



With some diffidence the author places in the old-established genus 

 Trochus 16 species, which all occur in the limestone strata, none 

 having yet been met with in the underlying shales. This genus has 

 hitberto been regarded as commencing in the Devonian, but the 

 author believes that the close resemblance in outer form of these 

 Silurian species justifies their inclusion in this genus, although, 

 neither the opercula, nor traces of the nacreous layer, have as yet 

 been discovered, and the microscojDic structure of the shell is not 

 preserved. 



A new genus, Pycnomphalus, is formed for trochiform or globose 

 shells with a thick callosity on the inner lip surrounding the 

 umbilicus. The genus is allied to Umbonium {= Botell a, Jjam.). 



In the family of the Turbinidse are ranged the genera Oriostoma, 

 Mun. Chal. ; Cydonema, Hall ; Trochonema and Euuema, Salt. ; and 

 Craspedosloma, n.g. Many of the forms of this group yet retain the 

 nacreous lustre of the inner shell-layer, and they possess a solid 

 shelly operculum, not infrequently found in situ. Under Oriostoma, 

 Mun. Chal., are included the familiar forms hitherto known as 

 Euomphalus discors, E. rugosus, and E. sculptus. Sow. 



A new genus, Autodetus, is created for the peculiar minute attached 

 shells placed by Schrenk under Capulus. 



Bulopea, Hall, with five species, is placed in the Litorinidas, and 

 Callontma, Hall, with Holopella, M'Coy, in the Scalaridte. Macro- 

 chilina, Bayle, with three species, is included in the Pyramidellidse. 



The genus Snbulites, Conrad, gives its name to a family, which, with 

 Euchrijsalis, Laube, and the provisional genus Onychochilus, Linds., 

 includes the earliest known representatives of the Holostomata. 



Before concluding our notice, we must express our admiration at 

 the beautiful manner in which the plates are executed. Tlie minutest 

 details of the surface-markings of the shells are shown with 

 marvellous clearness and precision, and the shells themselves are,. 



