TKTGOXIDJE. 
1 53 
was first figured by Yolta 1 , under the name of Baja muricata, and 
subsequently assigned to Trygonobatus vulgaris by de Blainville 2 . 
The same specimen was afterwards named by Agassiz 3 Trygon gaz- 
zolce ; and more recently Molin 4 and Baron de Zigno 5 have founded 
the genus Aleocandrinum upon a very similar fossil, which is not 
clearly distinguished either by the figure or in the descriptions. 
A second species was described by de Blainville ( loc. cit.) as Trygo- 
nobaius crassicaudatus, and likewise re-named by Agassiz (loc. cit.) 
Trygon oblongus. 
The small fragment of tail, with caudal spine, originally figured 
upon Yolta’s plate of “ Baja muricata ” has been identified with 
other more recently discovered specimens considered by Heckel 8 
and Molin 7 to be referable to Tceniura , and accordingly named 
T. Jcnerii. 
Another Monte Bolca fossil has been described by Molin 8 as re¬ 
ferable to Anacanthus , Ehrenb. (= Urogymnus, Mull. & Henle), and 
named A. zigni. Neither this description, however, nor Baron de 
Zigno's subsequent figure 9 appears to place the generic determina¬ 
tion beyond doubt. There are no dermal asperities such as specially 
characterize the living Urogymnus , and it seems quite possible that 
the brevity of the tail and the absence of caudal spines may be 
merely due to accident in preservation. 
The New Zealand fossil teeth and spines named Trygon ensifer ,j 
J. W. Davis (Trans. Koy. Dublin Soc. [2] vol. iv. (1888), p. 87,1 7 MY_ 
pi. vi. figs. 13-15), are evidently not Selachian. Equally doubtful 
also is tbe so-called Trygonpastinacoides, van Beneden (T. C.Winkler, 
Archiv. Mus. Teyler, vol. iii. 1874, p. 304), from the Bruxelliau 
Eocene of Belgium. , 
Genus XXPHOTRYGON, Cope. 
1//PC Qs'ls*-' c ck 
C C- 
[Arner. Naturalist, vol. xiii. 1879, p. 333.] & 
Syn. Heliobatis, 0. C. Marsh, Amer. Journ. Sci. [3] vol. xiv. 1877, 
p. 256 (undefined). 
Distinguished from Trygon by the cuspidate character of the teeth. 
1 Ittiolit. Yeron. 1796, p. 37, pi, ix. fig. 1. 
2 Youy. Diet. d’Hist. Yat. vol. xxvii. (1818), p. 336. 
3 Yeues Jahrb. 1835, p. 297. Poiss. Foss. vol. iii. p. 382**. 
4 Sitzungsb. math.-nat. Cl. k. Wiss. Wien, vol. xlii. (1861), p. 579. 
6 Mem. R. Istit. Yeneto, vol. xviii. (1874), p. 299, pi. xii. ( A. rnolinii). 
6 Sitzungsb. math.-nat. Cl. k. Ak. Wiss. Wien, vol. vii. (1851), p. 324, 
7 Loc. cit. vol. xlii. (1861), p. 581. 8 Ibid. p. 578, 
? Mem. R. Istit. Yeneto, vol. xviii. (1874), p. 298, pi. xi. 
