186 PROCEEDINGS OP THE ACADEMY OP 



there being a short mesial rounded lobe nearly reaching the mid- 

 dle of the valve, and near half way between this and each pos- 

 terior lateral margin, there is a long, slender, diverging lateral 

 lobe or impression. Dorsal valve shorter than the other, and 

 subcircular in form, its beak being apparently a little truncated ; 

 interior showing the same pitted appearance seen in the other 

 valve ; visceral and muscular impressions unknown. Surface of 

 both valves marked bj' fine concentric strise. 



Length, 0.26 inch ; breadth, 0.22 inch ; convexity, about 0.04 

 inch. 



From the foregoing description and illusti'ations, it will be 

 seen that this shell agrees exactly in the nature of its pitted inte- 

 rior, and in its furrow in a triangular false area, for the recep- 

 tion of the peduncle, with the tj'pe of Mr. Salter's genus Lingu- 

 lella (L. Davisii, Salter). The scars of the interior, however, do 

 not agree with the muscular impressions as made out by Mr. 

 Salter (see the cut fig. 3, reproduced from one of Mr. Salter's 

 figures). Still, as Mr. Davidson says, he could not see these 

 impressions as Mr. S. represented them, even on carefully exam- 

 ining his typical specimens ; it is quite probable that the latter 

 gentleman, although a careful, conscientious observer, may not 

 have made them out exactly right, especially as they are said by 

 Mr. Davidson to be very dimly defined. 



I have represented, in fig. 1, these scars of the interior of the 

 ventral valves as they appear to be in the form under considera- 

 tion, though they are obscurely defined, and seem to me to be 

 rather the impression of the visceral sack, than those ofthe mus- 

 cles. By comparing these impressions, as represented by the ac- 

 companying fig. 1, with those seen in the type of the genus Lin- 

 gulepis of Hall (reproduced by the annexed fig. 4), it will be 

 seen that they agree very nearl}-. I therefore suspect that Lmgu- 

 lep)is and Lingulella may yet be found to have been proposed for 

 the same genus, as we have here a shell witli the area and fur- 

 row for the peduncle of Lingulella^ possessing scars of the inte- 

 rior corresponding to those of Lingulepis. If so, our species 

 will have to be called Lingulepis Lamborni, as the latter generic 

 name has priority of date. It is barely possible, however, that 

 our shell ma}' belong to an intermediate undefined genus, possess- 

 ing some of the characters of both of the genera mentioned ; 

 especially as the type of Lingulepis shows no traces of the pitted 



[October 24, 



