FROM NORTHWESTERN EUROPE 75 
OccURRENCE. Dr. Zeiss, of Erlangen, has stated (personal communication 1965) 
that the material from Heiligenstadt occurs in the “ Schwammfacies’”’, There is 
no information available concerning the material figured by Rothpletz (1886). 
REMARKS. The species, as remarked by Schlotheim, is rare and this has probably 
been the cause of the confusion about which species the name senticosa should be 
difficulty has undoubtedly arisen through Buch (1838) citing the Schlotheim 
locality for his Terebratula senticosa and stating the horizon for this locality to be 
“ Dans les couches jurassiques inférieures, au-dessus du Lias”’. This statement 
seems to have lead several authors to reject the name senticosa when describing 
Upper Jurassic forms as they assumed Schlotheim’s species was from the Middle 
Jurassic. However, Rothpletz gives the topotype material as being “ Malm 
epsilon” in age and this agrees with the age given by Quenstedt (1871) for his 
Terebratula senticosa silicea from Sirchingen, while the material from Heiligenstadt 
in the collection of University of Erlangen is from the “ Malm delta ”’, 
A. (Echinirhynchia) lorioli (Rollier) 
(PL. 7, figs. 7-9, text-fig. 27) 
1850 Hemithiris senticosa (pars) Orbigny: 375. 
1857 Rhynchonella spinulosa (pars) Oppel): 608. 
1871 ?Tevebratula y alba Quenstedt: 114, pl. 39, figs. 63-65. 
| 1897 Acanthothyvis spinulosa (Oppel) ; Loriol: 146, pl. 27, fig: 17: 
1904 Acanthothyris spinulosa (Oppel) ; Loriol: 284-85, pli 27, fig. 45. 
| 1917 Acanthothyris Lovioli Rollier: 79. 
1917 ?Acanthothyris dealbata Rollier: 80. 
_ Emenpep DIAGNOSIS. Medium sized, pyriform or sub-circular Echinirhynchia. 
- Biconvex ; Tectimarginate ; beak adpressed to the brachial valve. 
STRATIGRAPHICAL RANGE, Oxfordian—the only exact records are from the trans- 
versartum zone. 
TYPE SPECIMEN, Lectotype, here selected, the original specimen figured by 
Loriol (1897) pl. 17, fig. 17, collected trom Montfaucon (Jura bernois). 
MATERIAL. 7 specimens from the collection of the B.M.(N.H.) two, BB.44166, 
BB.44167, from the Jura ; 10 specimens collected by Dr. Enay from the central 
French Jura ; 2 specimens collected by Dr. Evamy from Ain, 
_ Description. External characters. The species is normally biconvex but some 
specimens show a flattened brachial valve. The test is covered with many fine, 
bifurcating ribs bearing numerous fine spines. The beak is small and closely pressed 
to the brachial valve, obscuring the delthyrium ; beak ridges and interarea not 
developed. Growth lamellae are sometimes present but growth lines have not been 
observed. 
