186 TYLODINA. 
T. cirRina Joannis. Pl. 73, figs. 77, 78, 79, 80, 81, 82, 83. 
Shell short-oval, low-conic, rather thin; apex subcentral, directed 
slightly backward and to the left ; surface smooth, showing slight 
growth lines under the lens, a peripheral zone 38 or 4 mill. wide is 
membranaceous and squamose. Color pale yellowish, deeper toward 
the apex, with a variable number (6 to 22) of red-brown radial 
bands, coloring the cuticle, unevenly spaced, sometimes part of them 
disposed in pairs; apex whitish. The dark rays do not reach the 
apex, and are entirely epidermal, worn shells not showing them. 
Length 20, breadth 15, alt. 4 mill. 
Soft parts citron-yellow throughout, with slightly paler bands on 
upper surface of the foot ; gill pale yellow. Gizzard armed with a 
multitude of corneous, lamellose denticles. Jaws represented by 
fleshy prominences on each side of the mouth, covered with a trans 
parent chitinous cuticle. Radula with the formula 80 to 130.1.80 to 
130; usually about 90.1.90. 
Bay of Athens (Joannis) ; Palermo and Catania, Sicily (Arad. & 
Ben.) ; Sardinia (Cantraine) ; St. Helena (Smith); Lancerotte, Ca- 
naries (McAndrew). 
Tylodina citrina JoANNIs, Mag. de Zool., 1834, pl. 36, f. 1-5.— 
WEINKAUFF, Conch. des Mittelm. p. 178—ARaAp. & Ben., Conch. 
viv. Mar. Sicilia, p. 123—Monrs., Nuova Rivista Conch. Médit., p. 
49.— Kose xt, Prod. Faun. Moll. Eur., p. 273.— Tylodina (Joannisia) 
citrina Monts., Nomencl. Gen. e Spee. Conch. Méd., p. 149.— Vays- 
SIERE, Ann. Sci. Nat. (6), xv, 1883, p. 28, pl. 2, 3, f. 22-35; Re- 
cherches Zool., Opistobr., p. 152, pl. 5, f. 180-136.—Smiru, P. Z.S., 
1890, p. 299.—T. punctulata Raf., Gray, P. Z. S., 1856, p. 46. 
? Parmophorus patelloideus CANTRAINE, Bull. Acad. Brux., ii, p. 
395.— Umbrella patelloidea CantrR., Malac. Médit. et. Lit., p. 93 [pl. 
cp Oe aE 
?Tylodina punctulata RAFINESQUE, Journ. de Physique, de Chimie, 
d’Hist. Nat:; ete, Ixxxix, 1819 plas: 
?T. atlantica Gray, P.Z.S., 1856, p. 46=“ Umbrella (small),” Mco- 
AnpREw, Ann. Mag. Nat. Hist. (2), x, p. 104. 
The shell is larger and more depressed than in T. rafinesquit 
Phil. 
It is uncertain which species of Tylodina was known to Rafines- 
que. His description is as follows: 
“Genre 5. Tyroprna. (Mollusque). Corps rampant, a petite 
coquille dorsale extérieure membraneuse, sans spire, oval, & pointe 
