INSTITUTE OF SCIENCE, PHILADELPHIA. 77 



witnessed by Lyria harpula of Lamarck and one or two closely allied forms 

 from Barton and the Paris Basin. 



Section Volutopupa Dall. 



There are a few curious species in the Paris Basin Eocene which are really 

 aberrant species of Voliitilithes, if we may be permitted to judge from the 

 characteristics of their sculpture, which, as far as it goes, is sharp with a spinose 

 tendency. They agree in having a high, smooth nucleus of many volutions, 

 its characteristics being those of the Voliitilithes nucleus, but with more whorls, 

 indicating a longer intracapsular life. I regard these forms as constituting a 

 short lateral branch not extending higher than the Miocene, and not, as has 

 been thought by some, precursors of the Vobtta miisica type. For them it will be 

 convenient to form a section, Volutopupa, of the genus Volutilithes (PL 6, fig. 3 a). 



I have referred to the short step from Volutilitlies to Lyria. I figure a 

 species of Volittilitlies (Plate 6, figure i) which needs only to have the sharp- 

 ness of its sculpture a little rounded and the lirse effaced from its throat to be 

 an excellent Lyria. 



It is notable that after Volutilithes all the Volutidce are destitute of the 

 above-mentioned lirse. The denticulations of the edge of the lip as in Fulgoraria 

 rupestris are a function of the. external spiral sculpture and have nothing to 

 do with the true lir^. 



The internal thickening of the outer lip in the adult of some recent species 

 of Lyria has been regarded as a systematic character, but this is rarely found 

 in the fossil .species, and is exceptional even in the recent ones. It is a very 

 modern character, and may be regarded as a step toward the subgenus Encsta, 

 which I believe has not been found in a fossil state. 



The bulbous form of shelly nucleus, so well typified by the recent Fulgora- 

 ria rupestris, was initiated as early as the Eocene in America. It is very 

 difficult in rubbed specimens to distinguish the bulbous nucleus from some 

 variations of the Caricella nucleus (see PI. 7, fig. 4). I have even had my 

 doubts as to whether Fulgoraria was not Scaphelloid. Still, it seems pretty 

 certain that the protoconch in Fulgoraria is really shelly, and in EopsepJicea 

 membranous. The origin of the bulbous nucleus is indicated by the 

 minutely bulbous form of the apex in some individuals of Eocene and 

 Miocene forms oi Lyria. Vohita virescens (PL 6, fig. 7) is intermediate be- 

 tween the trochoid form of Valuta (typical PL 6, fig. 8) and the bulbous form of 

 Valuta vexilluvi. It seems very probable that the passage was from the tro- 

 choid to the small bulbous, and from this to the large trochoid and large 

 bulbous nucleus, respectively. I figure the tip of an unpublished Eocene 

 species of Valuta or allied genus, being an excellent example of the initiatory 

 bulb and the only specimen I have seen of the species (Plate 6, figure 5 a). 

 The sculpture, as far as it goes, is that of Volutilithes. 



As regards the Volutas with a Melonoid nucleus, which is not represented, 

 as far as I can discover, in any stratum older than the Quaternary, it is impos- 

 sible, in our present ignorance of the biography of the living Volutas, to say 



