STROPHALOSIA. 175 



Remarks. — The above-named specimens, which are too imperfect to admit of 

 specific determination, belong to some species of Productus which was covered by 

 numerous, but not crowded, coarse and very long spines, arranged more or less 

 regularly in transverse rows, and apparently most developed in the marginal 

 parts ; its umbo appears to be rather small and not very prominent ; its ears 

 are small, and bear a few very strong spines ; its shape is gibbose and rather 

 transverse ; its ventral valve has a small sinus down the back ; its dorsal valve 

 is geniculated, and crossed in the flat portion by rather numerous corrugations. 



To whatever species these shells belong, they appear to be distinct from the 

 species described above. Their surface may perhaps have been something like 

 P. spinulosus, Sowerby, 1 but they are distinguished from that shell by their sinus, 

 their larger size, and the much greater length of their spines. Not one of the 

 specimens is sufficiently good to enable us to ascertain its true shape or the 

 details of its surface-ornament. It is probably related to or even a variety of 

 Productus (or Productella) subaculeatus, Murchison, 2 but its spiues seem more 

 numerous than is usual in that species. 



2. Genus — Strophalosia, King, 1844. 

 1. Strophalosia productoides, Murchison, sp. Plate XXI, figs. 6 — 11. 



1840. Oethis peodttctoides, Murchison. Bull. Soc. Geol. Fr., vol. xi, p. 254, 



pi. ii, figs. 7 a — c. 

 1840. Lept^na capebata, Sowerby. Geol. Trans , ser. 2, vol. v, p. 3, pi. liii, 



fig. 4. 

 1865. Steophalosia peodtjctoides, Davidson (pars). Brit. Foss. Brach., vol. in, 



p. 97, pi. xix, figs. 13, 14 (only ?). 

 1871. — — Kayser. Zeitsch. Deutsch. Geol. Gesell., 



vol. xxiii, p. 638. 



Localities. — Baggy Point, Laticosta Cave, Croyde, Saunton, Braunton, Poles- 

 hill, Ashford Strand, Frankmarsh, Top Orchard, Roborough, Ashhill Quarry, 

 Pouch Bridge, South Petherwyn. It is abundant and often gregarious, but 

 rather local, being probably confined to particular zones in the Pilton series. 



Size. — A specimen measures about 50 mm. long by 55 mm. wide. 



1 1861, Davidson, "Brit. Foss. Brach.,' vol. ii, pt. 5, p. 175, pi. xxxiv, figs. 18—21; and 1880, 

 ibid., vol. iv, p. 299, pi. xxxvi, fig. 11. 



2 1865, Davidson, ' Brit. Foss. Brach.,' vol. iii, p. 99, pi. xx, figs. 1, 2 ; and 1882, ibid., vol. v, 

 p. 54, pi. iii, fig. 22 ; and 1893, Whidborne, ' Dev. Fauua,' vol. ii, p. 154 ; see also p. 156, pi. xvii, 

 fig. 12. 



