140 DUBLIN NATUEAL HI8T0ET SOCIETT. 



III. ** Loxonema constricta (Z. pulcherrima, M'Coy, Carb. Foss., 

 PL vii., Fig. 7). Loxonema sinuosa (Phil., Pal. Foss., Cornwall, 

 PI. xxxviii., Fig. 182)." 



From the neighbourhood of Clonmel. It is not an unfrequent fossil 

 in the Carboniferous Limestone of Ireland. 



IV. *' Machrocheilus acutus (Sow.). — WindmiU Quarry, near Cork. 

 (PL xi., Figs. 3 and 3)." 



These specimens would be referred by some to M. curvilineus, but the 

 truth is, that the species of this genus are very arbitrary ; and it appears 

 better for the present to consider them to belong to the well-known 

 form M. acutusy to which they are evidently closely allied. 



V. " Cerithioides telescopium (new). — Generic characters : same as 

 those of Cerithium, with the exception of the mouth, which is unknown. 

 Sp. character: Elongated, conical, whorls numerous (12), slightly con- 

 vex, smooth, with a faint subcentral band ; base of shell provided with 

 five or six well-marked longitudinal concentric grooves, extending from 

 the columella nearly to the outer border." 



From the "Windmill Quarry, near Cork. (PL x.. Figs. 2, 3, 4.) 



VI. ^^Cerithioides (ji. sp.). Carrigtuohill, near Cork. This is a spe- 

 cies distinct from the former, but not sufficiently well marked in the 

 specimens I have seen to admit of description. It has a narrow band on 

 the bottom of each whorl. It differs little from some specimens of Tur- 

 ritella suturalis ; and I am of opinion that the few carboniferous species 

 of Turritella which are still left in that genus should be removed into 

 another, as they are wanting in some of the characteristics of the true 

 Turritellidae." 



The provisional genus Cerithioides might be made to receive them, 

 as they are certainly not either Loxonema or Macrocheilus. The qua- 

 drangular shape of their mouth is a character of no value in a Palaeozoic 

 fossil, liable to the distortion produced by pressure. I have seen the 

 undoubted Turritella suturalis of the Carboniferous Limestone of Cork, 

 with the Melania- shaped mouth of Lonomena, produced by pressure, 

 which had, at the same time, squeezed the cross- section of the shell into 

 an ellipse, 



DESCRIPTION OF THE PLATES. 



Plate X. 



Fig. 1. Cerithium telescopium (recent), for comparison with the fossil 

 shells. 



Figs. 2, 3, 4 (new). Cerithioides telescopium {Haughton). Figs. 2 and 

 3 show the faint subcentral band ; and Fig. 4 shows the con- 

 centric basal grooves. 



Plate XI. 

 Figs. 1 and 1. Loxonema sulculosa {Phillips). 

 Figs. 2 and 2. Loxonema rugifera {Phillips). (New to Ireland.) 

 Figs. 3 and 3. Macrocheilus acutus (jax.) {Phillips). 

 Fig. 4. A new pateUiform fossil, allied to Acmwa, found in the Wind- 

 mill Quarry, near Cork. 



