MELVILL AND STANDEN : MARINE SHELLS FROM LIVELY ISLAND. IOI 



inclined to group it. There are also two specimens in Mrs. Blake's 

 collection. Recorded from Strait of Magellan. 



Monoceros calcar Martyn. — One example of this extremely vari- 

 able shell, of the form with exserted spire to which Lamarck gave the 

 name of M. imbricatus. The species occurs from Cape Horn to Chili, 

 where it attains its maximum heaviness of shell. Between this massive 

 form (M. crassilabrum Lam.) and the type there ranges a long series 

 of transitional forms, the more marked of which have severally been 

 named M. striatum Lm., M. glabratum Lm., M. globulus Sow., M. 

 costatum Sow., M. citrinum Sow., and M. acuminatum Sow. 



Crepidula dilatata Lm. — A good series. One specimen is the 

 form described as C. pallida by Broderip ; the rest are fairly typical. 

 The type is a large, rugose, inflated form, having the apex much 

 curved to the side of the shell, and the inner margin usually deeply 

 stained, or radiately lineated with chestnut. It has many synonyms, 

 e.g., C. depressa Dh., C. peruviana Lm., C. patula Dh., C. arenata 

 Brod., C. adolphei Less., C. grandis Midd., C. princeps Conr., C. 

 mummaria A. Gd., etc. It is generally distributed all along the 

 western coast of America, from Patagonia to Alaska, and also Kam- 

 chatka. 



Calyptrea (Trochita) radians Lm. — Three specimens, all of 

 them identical with C. corrugata Rv. Other synonyms are C. peru- 

 viana Dh., C. co?icamerata Martini, C. costellaria Phil., C. trochiformis 

 Gm., C. trochoides Dillw., C. araucana Less., C. sordida Brod., and 

 C. spirata Forb. It is recorded from Chili and Peru 3 also from the 

 Island of Inagua, Bahamas (Tryon). 



Natica impervia Phil. — Two typical specimens. In this species 

 the callus completely fills the umbilicus. Magellan's Strait (Tryon). 



N. magellanica Phil. — Three. Tryon appears to think this may 

 be a form of N. patagonica Phil., from Strait of Magellan. 



Scalaria (Opalia) magellanica Phil.— Two typical specimens. 

 Also sent by Mrs. Blake. 



Photinula expansa Sow.— Three specimens, all of the typical 

 light olive colour, with green and iridescent interior. It also occurs 

 at Kerguelen Island, Strait of Magellan, and South Georgia. The 

 principal synonyms are Margarita expansa Sow., Trochus expansus 

 Phil., Photina expansa A. Ad., Margarita hilli Forbes, etc. 



P. taeniata Wood. — Several typical examples of this, the largest 

 and most striking species in the small group of Margarita-like 

 shells found only in Antarctic America, for which H. & A. Adams 

 instituted the genus Photinula. It is imperforate, with a brilliantly 

 nacreous interior, and easily recognizable by the spiral pink bands 

 and lines on a shining white ground. The synonymy .is extensive, 



