26 
certainly knonn to range above the llluntic formation; at any rate, the 
typical forms all occur between the Bunter and the llliietic. Presumably, 
tliercforc, Aphnelopis does not represent an earlier period than the Liassie. 
With regard to the remarkahlc genus, Aeihcolcpis, it can only be 
considered as a similarly s])ecialised ally of Dapedius. The Bapedioid fishes are 
almost exclusively coniined to the Lias, only imsatisfaetory fragments occurring 
above and below. Aeihcolcpis is thus, at least, a typically Jurassic iisli. 
Arclueomtcne, again, is a typical member of the Pholidophorida', 
except as regards its cycloidal, deeply imbricating scales ; and although this 
family ranges from the Li)per Trias to the Upper Jurassic, it is especially 
characteristic of tin' Lias, 
All the preceding genera, however, are rare in the Talbragar tish- 
bcaring stratum, comjiared with the great shoals of Leptolcpis. These fishes 
occur ill hundreds in all stages of gixnvth from the small fry to the stout 
adult ; and the variations to bo observed in the different specimens are so 
great that it is ditficult to determine the number of species. Now, no typical 
example of Leptolcpis has hitherto been discovered below the Lias ; and even 
the forms recorded from the lower division of this formation are doubtful.^ 
It is a very abundant fish in the Upper Lias, and ranges throughout the 
.lurassic Series, probably becoming extinct before the Cretaceous period and 
the Liassie forms, which arc of comparatively small size, can always be 
distinguished from those of the Ujiper Oolites by the simple character of 
their vertebral centra. In a Liassie species the vertebral centrum is a simple, 
constrictinl cylinder ; in adult individuals of a sjiecies from the Solenhofen- 
stone (Lower Kinuncridgian), the centra are more or less strengthened by a 
])eri]dieral ossitication in longitudinal streaks. The Talbragar species of 
Leptolcpis belong to the former category, and thus, prcsumtibly, represent a 
lower horizon than the Upper Jurassic. 
To sum up: Aphnclcpis is a specialised 'friassic lish. ^Llhcolcpis and 
Archicomtcue are advances, respectively, u})on the Liassie Bapedioids and 
Pholidophorids, rvliile the spcei('s of Leptolcpis more resemble those of the 
L'ppcr Lias than those of the Lower Kinuncridgian. The Talbragar fish- 
faiiiia is, therefore, probably, not ('arlier than the Upper Lias, and may be 
referable to the Lower Oolites. 
* Tlie so-eallod I,eplohpix raudalix (Aifassi/,, I'oiss. Foss., ] [. Pt. ii, ]i. 133) from the l.ower Lias of Lyuie 
Tios'is, is ]iroveil not to belong to this genus by tlie presence of conspicuous fulcra and other cduiracters. Leptolcpis 
Bronni has been erroneously recorded from the Lower fans. 
- The so-called Leptolcpis vcocoiniensis and Tj. Xeuitinpri do not pertain to Ibis genus, if Bassani’s outline- 
skelches of the jaws are correct (Denkschr. k. Akad. Wiss,, math.-uaturw. Ci., 18S3, XLV, pp. 201-207, pi. II, figs. 
1 - 10 .) 
