122 CEETACEOUS PELECYPODA 



All Tjullinid^ are inhabitants of sandy shores ; they all buiy in mud, and 

 the "Teater number are purely marine species. Of the garinje which are more; 

 numerous in Austi-alian seas than anywhere else, there are about 120 species 

 known- of tisllinin^ which are in all tropical seas numerous, but largest and finest 

 in the eastern seas, there have been as yet about 3G0 species described. 



Cretaceous species of Tkllinid^e. 



Pictet and Campicbe in their review of the cretaceous species of this family refer them to 

 the genera Tellina, Arcopaffia, Psammolia, Sanguinolaria, and Mactnmya, (see Pal. Suisse, 4™' 



ser., 3"« part., pp. 133, &c.). 



1, Mactromi/a Couloni is the type of the genus; no other species is as yet known, and it is no 



doubt necessary to be very careful in transferring an imperfect fossil shell from one genus into 

 another for the confusion is in such cases often endless, and no benefit results either to the con- 



chologist or the geologist. 



2, Of Sanguinolaria also only one species bas been described, S. crelacensis, Conrad, from 



Alabama ; it bas quite the form of recent species of that genus, but the hinge-teeth bave not been 

 observed on tbe fossil. I cannot see for what reason the shell has been referred to Cyprimeria by 

 the same author (Am. Jour. Conch., iii, p. 9). 



Gari and allied genera. I have already mentioned that there is great difficulty in determining 

 which of the species usually quoted as Gari (= Psanmobia) really belong to that genus and which 

 to others. Jud"-ing from the preparation of the hinge-teeth of the two species which occur in the 

 Austrian Gosau formation, and of three species from the South Indian cretaceous rocks, I came to 

 the conclusion that these species do not even belong to the sub-family garinje, but must be classed 

 in a separate genus in the TAPESlNSl, (family Yeneridje). However, from want of sufficient 

 data reo^ardino- the hinge-teeth of other species, I shall be obliged to retain here those species which 

 are closely allied in form to Gari and others, though this statement must be accepted with the 

 distinct understanding that there is as yet not a single case known in which one of those species 

 has been satisfactorily ascertained as belonging to any of the genera of the garinje. 



Z-h.— Gari Guilleroni, feuuis and J'alangiensis, have the general form of P««wwoco/a, l)ut are 



rather less high. 



6.8. Gari Esclieri, intermedia and Sfi'ileri, have tbe posterior end radiately ribbed; there is a 



large number of such recent forms of Gari, they are chiefly of small size. 



Gari compremi, d'Orb., sp., Solen elegaiis, Math., [non d'Orb. or Desh.], iwpar, Zittel 

 { = elegans, d'Orb.),* discrepans, Duj., Aniandi, Coq., (apparently closely aUied to the last), and 

 Suessi, Zitt., &c., are all species of tapeslwe, as I shall state in more detail subsequently. 



Gueranger's (Album paleont., 1SC7, pi. xv,) three species, Capsa Cenomaneiisis, Colona and 

 concentrica, are closely allied to d'Orb igny's eleg am =^ ZiiteVs Ps. in/par, and no doubt also 

 belong to the same type of tapesin^. 



Gari texta, Gabb, (Pal. Calif, I, p. 155,) has the general form of the genus, but the pos- 

 terior plicature is apparently indistinct, as in Hiatula. 



I may here mention the peculiar shell described by Nillson as Venus!' exuia ; it may prove 

 to be a species of the garinje (Petr. Suec, p. 17). 



* Matlieron's name elegans must stand for the Tapes-iovm; Dcshayes' species elegans is a Gari; 

 d'Ovbigny's name elegam was changed into impar by Zittel, who (Denksch. Akad., Wien, vol. xxiv, p. 120,) iden- 

 tifies the Gosau with the French species, although, judging from the figures, there are considerable differences between 

 the two ; the author does not say whether he liad compared authentic specimens of the latter with the foiiner. 



