108 DEVONIAN FAUNA. 



five very regular, minute, parallel, very distant, erect threads. Shell-structure 

 apparently thick. 



Size. — Height 12 mm., length 24 mm., depth of one valve 4 mm. 



Localities. — Two specimens from Fremington are in the Barnstaple Athengeum ; 

 one defective specimen from Frankmarsh in my Collection ; and one very 

 obscure specimen from Barnstaple in the Woodwardian Museum. 



Remarks. — Phillips's description of his Nuciila latissima is only — *' its great 

 width is its chief characteristic." His figure is only the outline and hinge ; 

 his locality Pilton. All that can be said is that the present shell seems to agree 

 exactly in shape, though Phillips's drawing perhaps implies rather fewer teeth, 

 I have been unable to find his type specimen, and can therefore only refer our 

 shell to his species doubtfully. 



Again, Phillips identifies a shell from Meadfoot Sands with Sowerby's Cucullgea 

 ovata^ and at the same time refers to a small doubtful specimen from Pilton. 

 To whatever species the Meadfoot fossil may belong, the specimens before us 

 appear distinctly to differ from Sowerby's shell by their much greater transverse- 

 ness and less ovoid shape, though, as he has only figured a cast, the ornament 

 cannot be compared. The doubtful specimen which he quotes from Pilton 

 may possibly belong to the present species. 



The existence of a clavicular process is not very certain, as the surface of the 

 figured specimen is decayed about that part. Hence the genus must remain doubtful. 



Affinities. — Nucula Krotonis, F. A. Romer,^ which is the same as Cncullella 

 temiiarata, Sandberger," is similar and possibly may prove identical. It seems, 

 however, to differ in its more ovate shape. It appears, according to Beushausen, 

 not to have a true clavicular ridge. 



Ct. lirata, Phillips, sp., has a slighter hinge-line, fewer and stronger threads, 

 no clavicular ridge, and a posterior constriction and emargination. 



Nucula tumida, F. A. Romer,* and N. iwlydonta^ F. A. Romer,^ seem shorter 

 and more oval, and the former at least has no clavicular ridge. 



Nuculites ohlongatus, Conrad,^ sp., which HalF compares with Nucula {Niicu- 

 lites) ovata, Phillips, appears to differ in having longer, closer teeth, forming an 

 unbroken sweep and not extending so far in front. 



1 1839, Sowerby, in ' Murchisoii Sil. Syst.,' p. 602, pi. iii, fig. 12 b. 



2 1850, r. A. Eotner, ' Beitr. Harzgeb.,' pt. i, p. 1.3, pi. iii, fig. 5, and 1895, Beushausen, * Abhandl. 

 k. Preuss. Geol. Landes.,' n. s., pt. 17, p. 72, pi. v., figs. 24 a, h, 25. 



^ 1853, Sandberger, ' Verst. Rhein. Nassau,' p. 276, pi. xxix, figs. 4, 4«. 



* 1843, ^. A. Romer, ' Verst. Harzgeb.,' p. 24, pi. xii, fig. 30. 



' 1855, F. A. Romer, ' Beitr. Harzgeb,,' pt. 3, p. 12, pi. iii, 6g. 8. 



6 1841, Conrad, ' Geol. Surv. N. Y., Ann. Rept.,' p. 50, plate, fig. 8. 



7 1885, Hall, ' Pal. N. T.,' vol. v, pt, 1, No. 2, p. 324, pi. xlvii, figs. 1—12. 



