R. ETHERIDGE, JUN., ON A LOWER-CARBONIFEROUS SPIRIFERINA. 463 



In concluding this part of my communication, it may be well to 

 shortly recapitulate the chief peculiarities of this remarkable form 

 of Productus. First, its parasitic habit, the indication of which can 

 be seen in some form or other throughout nearly the whole suite of 

 specimens, either as a groove in the ventral valve from the beak 

 forwards, or as a distortion, or by a curving and twisting of the 

 spines. Secondly, the characteristic and well-defined nature of the 

 concentric ornamentation, and, when preserved, the elongated 

 clasping spines. Thirdly, the well-marked mesial ridge in the interior 

 of the dorsal valve, and its separation into two portions, as in P. 

 scabriculus, Martin. Fourthly, the absence of a sinus in the ventral 

 valve. Fifthly, the well-marked peculiarities of character continuously 

 traceable from the smallest to the largest specimen, and no apparent 

 gradation onwards to some well-known species. 



5. Locality and Horizon. — Skateraw Harbour, near Dunbar, plenti- 

 ful; East Barns Quarry, near Dunbar, not common ; Carlops Quarry, 

 near Carlops, Peeblesshire, very rare ; shale over the No. 2 Lime- 

 stone (=Hosie Limestone) of the Lower Carboniferous Limestone 

 group of the Midlothian series. 



Collected by Mr. James Bennie. 



When collecting fossils from the Calderwood series in the East 

 Kilbride district, Lanarkshire, a year or so since, Mr. Bennie noticed 

 bodies with radiating processes adhering to Encrinite stems, which 

 he thinks may be this Productus. 



II. On a Small Spirieerina. 



I take this opportunity of figuring and briefly describing a small 

 shell which may be new, in the hope that the attention of collectors 

 may be called to it. As we at present only possess one speci- 

 men, I shall content myself with merely placing it on record, and 

 await tho discovery of other specimens, when we may be better able 

 to judge of its specific value. 



Spiriferina, sp. 



Specific Characters. — Small, transversely oval, wider than long ; 

 ventral valve the more convex of the two. Hinge-line less than the 

 width of the shell ; cardinal angles rounded ; beak incurved and 

 moderately produced above the area, which is concave and trian- 

 gular ; fissure wide. Ventral valve with a simple shallow sinus, and 

 three rounded ribs on each side, the outer ones indistinctly marked. 

 In the dorsal valve the mesial fold is composed of a single rib, larger 

 than either of the others, two on each side. No laminae of growth. 

 Shell-structure perforated by minute tubuli giving to the surface a 

 dotted appearance. 



Obs. — This little shell differs from Sjpiriferina cristata, Schl., var. 

 octoplicata, Sow., by the hinge-line being less than the width, by its 

 very rounded cardinal angles, perfect simplicity of the mesial fold 



Q. J. G. S. No. 128. 2 k 



