LOWER LIAS OF ROBIN HOOD'S BAY 



123 



Subfamily AGASSICERATINAE Spath. 1924 

 Genus AGASSICERAS Hyatt, 1875 



Well-preserved Agassiceras scipionianum (d'Orbigny) and the 

 smaller, smoother species A. personation have been figured before 

 from Robin Hood's Bay and are common in old collections, but none 

 were found by Bairstow. Agassiceras mainly characterizes the 

 Scipionianum Subzone, just below the lowest horizon exposed in 

 Robin Hood's Bay, so, although it is possible that some of them came 

 from beds 421 or 422, it is more likely that they were derived from 

 Glacial Drift. 



Agassiceras personatum (Simpson, 1843) 



1843 Ammonites personatus Simpson: 9. 



1920 Agassiceras personatum (Simpson); Buckman: pi. 187, figs 

 1, 2 (holotype, WM 2125), 3, 4 (paratype WM 67). 



Remarks. A small smooth species. 

 Agassiceras scipionianum (d'Orbigny, 1844) 



1844 

 71855 



1876 



1961 



71962 



1994 



Ammonites scipionianus d'Orbigny: 207, pi. 51, figs 7, 8. 



Ammonites Hiatus Simpson: 39 (non Ammonites Hiatus 



Simpson, 1843: 10). 



Arietites scipionianus (d'Orbigny); Blake: 287, pi. 5, fig. 3 



(BM C. 17909; locality not recorded, but the preservation is 



like that of other specimens from Robin Hood's Bay). 



Agassiceras scipionianum (d'Orbigny); Dean etai: pi. 65, 



fig. 3 (BM 37909). 



Agassiceras illatum (Simpson, 1855, non 1843); Howarth: 



102, pi. 15, fig. 1 (holotype, WM 84). 



Agassiceras scipionianum (d'Orbigny); Fischer: 53, pi. 16, 



figs 1 (lectotype), 2 (both from France). 



Agassiceras decipiens (Spath, 1923) 



1923b Aetomoceras decipiens Spath: 72. 



Remarks. Spam's three syntypes are BM C. 22067a, C. 22067b 

 and a specimen at the top of the block WM 67 as figured by Buckman 

 (1920: pi. 187, fig. 3), all from Robin Hood's Bay. Of these, C.22067a 

 is here designated lectotype; it is similar to A. scipionianum 

 (d'Orbigny), but has slightly more ribs. 



Genus EUAGASSICERAS Spath, 1924 



Euagassiceras resupinatum (Simpson, 1843) 



PL 1, fig. 5 



1843 Ammonites resupinatus Simpson: 15. 



1844 Ammonites sauzeanus d'Orbigny: 304, pi. 95, figs 4, 5. 

 1855 Ammonites transformatus Simpson: 91. 



1889 Coroniceras sauzeanum (d'Orbigny); Hyatt: 184, pi. 6, figs 

 4,6-9. 



1909 Agassiceras resupinatum (Simpson); Buckman: pi. 6 

 (holotype, WM 96; ?from bed 421 or 422). 



1913 Agassiceras transformatum (Simpson); Buckman: pi. 75 

 (holotype. WM 279, ?from bed 421 or 422). 



1913 Defossiceras defossum (Simpson, 1843); Buckman: pi. 76 

 ( WM 103, a paralectotype, presumably also from beds 421 — 

 422; see Donovan & Forsey (1973: 13) for interpretation of 

 Defossiceras and its type species). 



1994 Euagassiceras sauzeanum d'Orbigny; Fischer: 84, pi. 16, 

 fig. 3 (holotype, from France). 



Range. Beds 421.4-426.1, Sauzeanum Subzone; 38 specimens, 

 of which the best preserved are in beds 42 1 and 422. 



REMARKS. Typical examples of Euagassiceras occur in beds 421 

 and 422, and it is likely that the holotypes of Simpson's species E. 

 resupinatum and E. transformatum are from those beds; both species 

 are synonyms off. sauzeanum (d'Orbigny, 1844), and E. resupinatum 

 (Simpson, 1843) is the senior name for this species. 



Subfamily ASTEROCERATINAE Spath 1946 

 Genus ASTEROCERAS Hyatt, 1867 



Asteroceras obtusum (J. Sowerby, 1817) 



1817 Ammonites obtusus J. Sowerby: 151, pi. 167. 



1966 Asteroceras obtusum (J. Sowerby); Guerin-Franiatte: 294, 



pi. 170 (lectotype, Oxford University Museum, OUM 



J. 1 194, from Charmouth, Dorset). 



RANGE. One specimen in bed 446.32, Obtusum Subzone. A single 

 Asteroceras sp. indet. in bed 446.3 1 is the lowest recorded Asteroceras 

 in Robin Hood's Bay. 



Asteroceras confusum Spath, 1925 



PI. 1, fig. 4; PI. 2, fig. 1 



I Arietites obtusus (J. Sowerby); Wright: 293 (1881), pi. 21, 

 figs 3,4(1 880) (holotype of Asteroceras confusum Spath). 



1925rt Asteroceras confusum Spath: 300. 



1966 Asteroceras confusum Spath; Guerin-Franiatte: 296, pi. 172 

 (holotype, BM C.2223, from Bredon, Worcestershire). 



Range. Five specimens in beds 446.32 and 446.33, Obtusum 

 Subzone. 



Remarks. A. confusum has thicker whorls and more prominent 

 grooves bordering the keel on the venter than A. obtusum. 



Asteroceras stellare (J. Sowerby, 1815) 



1815 Ammonites stellaris J. Sowerby: 2 1 1 , pi. 93. 



1880/81 Arietites stellaris (J. Sowerby); Wright: 295 (1881), pi. 22, 



figs 3-5 (1880) (lectotype, BM 43969a, from Dorset). 

 1882 Aegoceras sagittarium (Blake); Wright: 355, pi. 52, figs 1- 



PLATE 2 



Fig. 1 Asteroceras confusum Spath. Bed 446.32, CA 301 1 , x 0.6. 



Fig. 2 Asteroceras blakei Spath. Bed 452, CA 2990, x 0.5. 



Figs 3, 5 Caenisites turneri (J. de C. Sowerby). Bed 433.3. 3, CA 3194. 5, CA 3197; the asterisk marks the probable end of the phragmocone. 



Fig. 4 Aegasteroceras crassum Spath. Bed 458.2, CA 3048; a body chamber fragment. 



Fig. 6 Gagaticeras neglectum (Simpson). Bed 468, CA 3326; probably wholly septate. 



Fig. 7 Gagaticeras exortum (Simpson). Bed 468, CA 3292; the asterisk marks the probable end of the phragmocone. 



Fig. 8 Eparietites bairstowi sp. nov. Paratype, bed 455.5, CA 3218; probably wholly septate. 



All figures natural size, except Figs 1 and 2. 



