126 



DISCOVERY REPORTS 



Family CALYPTRAEIDAE 



Genus Trochita Schumacher, 1817 



Type: Patella trochiformis Gmelin = Infundibulum of Tryon, 1886 (non Montfort, 18 10)* 



This genus covers shells with a circular outline, a conical spire with a central nucleus and a moderate 



sigmoid outline to the edge of the septum. The shape and central position of the nucleus recall both 



the English Calyptraea sinensis Linn, and the New Zealand genus Zegalerus. The former, however, has 



a more elaborate septum which terminates as a tongue forming both a spiral umbilicus and a deep sinus 



at its outer extremity. In Zegalerus the septum is gently concave to almost straight. A second Austro- 



neozelanic genus, Sigapatella, has a simple arcuate septum as in Zegalerus, but the shell has more 



rapidly increasing whorls with the apex off centre (see Fig. E). 



The radula of Trochita trochiformis (Fig. J, 40) differs from that of Calyptraea sinensis (Fig. J, 38) 

 and Sigapatella terraenovae (Fig. J, 39) in having a central tooth with a massive cusp and very weak 

 side denticles, and perfectly plain marginals. 



Fig. E. Septa in Calyptraeidae. (1) Calyptraea sinensis (Linn.), England. (2) Trochita trochiformis (Gmelin), Falkland Is. 

 (3) Trochita georgiana n.sp., South Georgia. (4) Zegalerus tenuis (Gray), New Zealand. (5) Sigapatella novaezelandiae 

 Lesson, New Zealand. 



Trochita trochiformis (Gmelin) 



Patella trochiformis Gmelin, 1791, p. 3693. 



Patella trochiformis Dillwyn, 1817, p. 1018. 



Calyptraea radians Lamarck, 1836, p. 626. 



Calyptraea costellata Philippi, 1845 a, p. 62. 



Trochita corrugata Reeve, 1858, fig. 96. 



Calyptraea (Infundibulum) radians Tryon, 1886, p. 121, pi. 35, figs. 84-88. 



Calyptraea costellata Strebel, 1906, p. 159, pi. 13, figs. 88-92, 94-97. 



Calyptraea costellata Melvill & Standen, 1907, p. 100. 



Calyptraea costellata Strebel, 1908, p. 59. 



* Montfort's name would undoubtedly have priority if the extremely poor figure of his genotype, 'Infundibulum typus', was 

 determinable and found to be a Calyptraeid as the figure suggests. Thiele (1929, p. 55) interprets Montfort's Infundibulum 

 as a section of Trochus. 



