INSTITUTE OF SCIENCE, PHILADELPHIA. 7g 



In America, Caricclla,-as far as known, is confined to the Eocene and com- 

 prises, beside the above-mentioned typical species, C. doliata, prisca, demissa, 

 pyruloides, bolaris, and subangidata Conrad; C. Heilprini Dall (C Bmtdoni 

 Heilprin, Proc. A. N. S. 1880, pi. xx. fig. 15, not of Deshayes), C. retiailata 

 Aldrich, C. Lcaiia and C. podagrina Dall ; and abroad C. Weiherelli Sowerby, 

 There is one Eocene species, Valuta Showaltcri of Aldrich, which seems to 

 make a passage to Scaplidla proper by way of the Miocene 5. solitaria Con- 

 rad, and toward Aurinia by way of Voliitifusus typus Conrad, 



Genus LAPP ARIA Conrad, 1855. 

 Plate 6, fig. 6. 

 Type Mitra diimosa Conrad, Claiborne sands, 1855 = Mitra paclilis Conrad, 1833, and 

 Valuta dubia H. C. Lea, 1841. 



This Eocene offshoot from the Scapliella series is characterized by the 

 Caricella nucleus and sculpture of early whorls; by a solid, compact mitriform 

 shell of which the aperture does not exceed half the length of the whole shell ; 

 by a short recurved canal with a well-marked siphonal fasciole; four stout sub- 

 equal plaits, counting that on the edge of the pillar ; and by a tendency to 

 nodulation or projecting sharp spires on the shoulder of the whorl. There 

 are three nominal species, the variations of which are such that I expect fur- 

 ther study will reduce them all to varieties of one form, under pactUis, the old- 

 est specific name. The other names are Mitra dumosa Conrad and Mitra 

 Mooreana Gabb. Taken together, they extend from the early to the later 

 Eocene, but are not known in the Miocene at present. 



These shells are Scaphellas in the larval and adolescent state, and take on 

 mitroid characteristics only near maturity. No true Mitra exhibits such a 

 nucleus, and they are beyond a doubt properly referred to the Volutidce, where 

 their peculiar characters entitle them to generic rank. This group probably 

 originated about the same time as Caricella, and from the same stock. 



Genus SCAPHELLA Swainson, 1832. 

 Plate 7, figure 9. 

 Scaphella (Swainson) Dall, Blake Gastropoda, Bull Mus. Comp. Zool. xviii. p. 147, 18S9. 

 Type Scaphella (^Valuta) jimonici Hwass ; Florida Strait. 



Scaphella as above typified is the descendant in one line, as Aurinia is in 

 another, from the Eocene Caricellas. Every character of both can be fore- 

 shadowed by that exhibited by some of the Eocene shells. In C. prisca we 

 have definitely exhibited the color-pattern alike of Scaphella junonia and Auri- 

 itia dubia. The odd little riblets on the early whorls of C. prisca are paral- 

 leled in every recent species of Aurinia, as is the fine spiral striation. But the 

 plaits are more like those of Scaphella ; in Aurinia they are fewer in number 

 and obsolete toward maturity. The pillar is usually pretty straight in Cari- 

 cella, but in C. prisca it is curved. It is, in fact, impossible to frame any diag- 

 nosis which shall include the recent and fossil Scaphellas and at the same 



