Plate XVII. 



Protoconcli and Early Conch JVhorls of Fusoid Shells. 



(Drawn by Miss Elvira Wood, U. S. G. S., Washington, D. C, formerly 

 Instructor in Palaeontology Massachusetts Institute of Technology.) 



(M. C. Z., Museum of Comparative Zoology, Cambridge; Acad. Sci., Museum 

 of the Academy of Sciences, Philadelphia ; Nat. Mus., National Museum, 

 Smithsonian Institution, Washington, D. C.) 



Page. 

 Figs. I. Fttsiis tnrricnlus, specimen, fig. i, pi. IT, showing tpical Fusiis proto- 



conch (M. C. Z. t,2„ X lo) 21 



2. Fusus longirostris, Pliocene (M. C. Z. 1213, X 10) 52 



3. Fusus longirostris, accelerated type. The first whorl of the proto- 



concli is restored. The second shows numerous crowded riblets 

 (B. S. S134, X 10) 52 



4. Fusus brcdcc. Protoconch and early whorls of specimen, fig. 8, pi. 



IV. The varix and riblets of the final portion of the protoconch 

 are shown ( M. C. Z. 1452, X 10) 60 



5. Lcvifusus? harrisi Grabau (Am. Nat., Vol. XXXVII, p. 527), show- 



ing the Fulguroid protoconch of the type. Lower Claiborne, 

 Texas (Acad. Sci. 6959, X 16) 86 



6. Fulgurofusus quercollis, showing the Fulguroid protoconch and 



nepionic stage (Acad. Sci. 9019, X 16) 86 



7. Lcvifusus trabeatus, showing a protoconch analogous to that of 



Falsifusus (Acad. Sci. 6955, X 16) 2 



8. Latirofusus ? interstriatus (Heilprin), showing the Falsifusus type 



of protoconch (Acad. Sci. 6847, X 16) 2 



9. Falsifusus mcyeri, the apical w'horls enlarged, showing the Plenroto- 



moid protoconch (Nat. Mus. 129562, X 16) 81 



(190) 



