278 PHOTINULA. 



Genus PHOTINULA H. & A. Adams, 1854. 



Photinula H. & A. Ad., Genera Rec. Moll., i, p. 427 ; and of 

 recent authors.— Photina H. & A. Ac, P. Z. S. 1851, p. 191 (not of 

 Burmeister). — Margarita (in part) of authors (not of Leach). 



The genus Photinula was instituted for Margarita-like shells 

 with imperforate axis, confined to Antarctic America in distribution. 

 The species are few and very variable. 



P. T^NiATA Wood. PI. 44, figs. 18, 19. PI. 64, fig. 37. 



Shell imperforate, depressed, conoid, thin, shining, white, uuicolored 

 or Avith numerous spiral pink stripes and lines ; surface smooth ; 

 spire conical, apex acute, the first three whorls encircled by three 

 coarse lirse ; whorls 6, the last rapidly increasing ; aperture oblique, 

 rounded-rhombic, with a thin, finely folded, brilliantly iridescent 

 layer of nacre inside; peristome simple, thin; columella broad, 

 reflexed, appressed, arising from a small pad of callous on the base 

 of the shell. Alt. 21, diam. 26 mill. ; alt. 17, diam. 23 mill. 



Sts. of Magellan ; Falkland Is. 



Trochus tceniatus Wood, Index Test, suppl., t. 5, £ 12.— Philippi, 

 Conchyl. Cab., p. 251, t. 37, f 12.— Fischer, Coq. Viv., p. 319, t. 

 100, f. 2. — Margarita tceniata Sowb. Conch. Ill, f 2 ; in Reeve, 

 Conch. Icon., xx, f. 4. — Reeve, Conch. Syst., t. 227, f 2. — T. bicolor 

 Lesson, Voy. de la Coquille, p. 345, t. 16, f 3. — Photinula ta^niata 

 Chenu, Manuel, i, p. 361, f 2681. — Margarita ccerulescens King, 

 Zool. Journ., v, p. 346, no. 54. — Sowerby in Reeve, Conch. Icon., 

 XX, f 12. — Trochus ccerulescens Philippi, Conchyl. Cab., p. 250, t. 

 37^ f_ 11, — Watson, Rept. Challenger Gasterop., p. 68.; — Tr. lineatus 

 Phil., Arch, f Naturg. 1845, p. 56 (not of Da Costa). — Margarita 

 maxima Hombron et Jacquinot, Voy. au Pole Sud, p. 59, pi. 14, 

 f, 32, 33 (not T. maximus Koch). — Photina coerulea A. Ad., P. Z. S. 

 1851, p. 1^1.— Photinula ccerulescens Ads., Genera, i, p. 427. — 

 T. homhroni Fischer, Coq. Viv., p. 320, t. 100, f. 3. — T.purpuratus 

 Forbes, P. Z. S. 1850, p. 372, t. 11, f 11. 



A large handsome species, easily recognized by its spiral red stripes 

 on a white ground. 



Var. ccerulescens King. PI. 44, rigs. 18, 19. 



More depressed ; aperture more oblique ; color ashen or fleshy, 

 with spiral lines and bands of blackish-blue. 



