JIOORK — ON NEW liliAClIIOrODA, KTC. 
445 
Under tlio microscopo the shell shows a number of widely- 
separated, circular punctuations, which are arranged in longitudinal 
lines. 
Lept;ena Davidsonu. Eug. Deslongchamps. PI. xiii., figs. 21, 22. 
The figures representing the above species are taken from speci- 
mens for which I am indebted to M. Eugene Deslongchamps, of 
Caen. They were found in the Upper Lias of May, associated with 
several of the species found in this country. It appears to be abund- 
ant in France, and to attain larger dimensions than any other liassic 
Leptasna. 
I have found a single dorsal valve of this species in the Upper 
Lias of Ilminster, which though not in good condition, sufficiently 
identifies the Leptcena Davidsonii as a British species. 
EXALANATION OP PLATE XIII. 
Fig. 1. Terebmtella Biickmanii, Woodward. Interior, showing the perfect loop. 
2. . Interior of shell much enlarged, showing the 
loop in its first stage. 
3. . Second stage of the loop, with a rudimentary 
reflected portion. 
4. . Tlurd stage, with the reflected portion of the 
loop now enveloped. 
5. . Perfect sheU, enlarged. 
6. Terehratula maxillata, Sowerby. Young shell, enlarged. 
7. . Interior, exhibiting the loop. 
8. Terebratella furcata, Sow. and Moore. Enlarged exterior. 
9. . Showing jiei'fect loop. 
10. . Profile of ditto. 
11. TerehratuUna, radiata, Moore. Perfect shell. 
12. . Exterior of ventral valve. 
13. . Interior, with loop. 
14. . Elongated variety, from Dudley. 
15. Zellomia glohata, Moore. Much enlarged. 
16. . Side view of ditto. 
17. . Interior of dorsal valve. 
18. Zellania oolitica, Moore. Perfect shell, much enlarged, showing punc- 
tuated structure. 
19. . Exterior of ventral valve, 
20. . Profile of sheU. 
21. Leptcena Davidsoni. Exterior, natm-al size. 
22. . Ventral valve, ditto. 
[The longitudinal lines indicate the sizes of the specimens, all of which are 
enlarged.] 
(To he continued.) 
