72 A CATALOGUE OF AUSTRALIAN FOSSILS. 
(Pelecypoda.) (Mid. and Up. Paleozoic.) 
Genus and Species. |: Peso References. Localities, &c. 
M. fragilis, Dana. Vide Notomya fragilis. 
M. gigas, Dana. Vide Pachydomus gigas, M‘Coy. 
M. gracilis, Dana. Vide Notomya gracilis, Dana. 
M. grandis, Dana. Vide Notomya grandis, Dana. 
M. Koninckii, W. B. Vide Notomya Koninckii, W. B. 
Clarke. Clarke. 
M. myiformis, Dana. Vide Clarkia myiformis. 
M. recta, Dana. Vide Notomya recta. 
M. valida, Dana. Vide Notomya valida. 
Genus Mytilus’, Linneus, 1758 (Systema, ed. 10, 1. p. 704; Lamarck, Prodrome, 
1799, p. 88; &c.)= Perna, Adanson, 1757.—Mytilacea-Mytilide. 
M. Bigsbyi, de Kon. |U.Pal.(Carb.)| *Foss. Pal. Nouv.-Galles du Sud, | Branxton, N. S. 
| 1877, pt. 3, p. 288, t. 21, f. 1. Wales. 
M. crassiventer, de |U.Pal.(Carb.)| *Foss. Pal. Nouv.-Galles du Sud, | Branxton, N. S. 
Kon. 1877, pt. 3, p. 288, t. 21, £. 2. Wales. 
Genus Notomya, M‘Coy, 1847 (Annals Nat. Hist. xx. p; 303; Stoliczka, Pal. Indica, 
11. p. 83) = Myonia et Meonia, Dana, 1847 (non Myonia, Adams, 1860); Cleobis, 
Dana, 1847; Pyramus, Dana, 1847.—Myacea-Saxicavide? 
N. axinia, Dana. U. Pal. (Carb.)| Cypricardia ? sinuosa, Dana,*Am. | Ilawara, N.S. 
Jour. Science, 1847, rv. p. 157; Wales. 
M. axinea, *Geol. U.S. Explor. 
Exped. p. 696, Atlas, t. 5, f. 5; 
C. sinuosa et M. axinia, Clarke, 
S. Goldfields, 1860, pp. 287, 
288. 
N. clavata, M‘Coy. |U.Pal.(Carb.)| *Annals Nat. Hist. 1847,xx.p.304, | Wollongong, N. S. 
t. 15, f. 4; *Proe. R. Soc. V. D. Wales. 
Land, 1851, 1. p. 327, t. 15, 
f.4; Plews, Mining Inst. Jour. 
1858, vi. pt. 3, t. 4; Clarke, 
8. Goldfields, 1860, p. 287. 
Notomya or Meonia may just as well belong to Pachydomus, and vice versa” (Pal. Indica, 111. p. 83). 
Meonia (Myonia), Cleobis, and Pyramus were proposed as new genera by Prof. Dana in 1847, but 
in the next year he suggested that the various species contained in the three so-called genera should 
be brought together under the one name Meéonia, “as the gradations are such that it is difficult 
to draw lines of distinction” (Amer. Jour, Sc. 1848, v, p. 434). Again he says, “the divisions may, 
perhaps, form sub-genera” (Geol. U. S. Explor. Exped. p. 694). The section Pyramus or Pyramia is 
stated to correspond with Notomya, M‘Coy, and is slightly antecedent to it in date. As, however, 
I agree with Dr Stoliczka in considering M‘Coy’s description ‘‘far more intelligible than that given by 
Dana of his genus,” and as in addition M‘Coy no doubt correctly indicated the affinities of his genus, 
I prefer to adopt the latter for the whole of the species which have been referred to these genera. 
In dealing with this portion of my subject I have experienced the utmost difficulty, and can only 
offer the present synonymy as a temporary solution, until some paleontologist is afforded an o 
portunity of working the subject out in detail. To his previous remarks on this subject Dr Stoliczka 
adds, “neither in the text nor Atlas of his later work does Dana mention which of the species belong 
to each of the three sub-genera; and from the descriptions and figures the reader will find it very 
difficult to arrive at anything like accuracy of determination.” 
' The name Mytilus should give place to that of Perna, Adanson, proposed in the Voy. aw 
Sénégal (p. 217). Although Adanson was not a binomial writer, Perna, like many other of his genera, 
was perfectly well characterised, and ought to be adopted, 
