Occasional Papers of the Museum of Zoology 53 



lower, sharper and more compressed, but widely spaced. Spiral sculpture 

 as weak as in typical lot. 



C15. Quite abundant; this lot was accidentally mixed with that from 

 the eastern escarpment of Seroe Djerimi (C17a and C15; 431 specimens). 

 By comparison of this mixed set with the other lot from Seroe Djerimi, 

 it is very evident that the shells from C15 are similar to those from C16, 

 but show still finer and more closely-spaced growth-costae. In addition, 

 the spiral sculpture tends to approach that of the next subspecies. 



This species appears to be quite similar to T. costata 

 ("Menke" Pfr.) (1846 ; Zeit. Mai., 47) in color and sculpture ; 

 the habitat of the latter is unknown. However, if the figure 

 (1846-9; Chemn., II, fig. ix-9, 10) is even approximate, the 

 much larger aperture of that species has its long axis almost 

 parallel to that of the shell, and the parietal angle is even more 

 markedly lobate than in T. rupis. I do not believe that T. 

 costata occurs in the Dutch Leeward Islands, as none of the 

 thousands of specimens examined by me shows any tendency 

 to approach this striking aperture. Probably the specimens 

 quoted by Vemhout (1914) belong to one of the subspecies of 

 T. muskusi. 



Tudora muskusi grandiensis, new subspecies 



Type locality: (C14) northern half of Seroe Grandi, south 

 of Sint Jan Baai, northern Curacao. 



Distribution : Curacao ; along western side, from Seroe 

 Baha So (4 specimens), to (at least) Seroe Grandi (C15, 14) ; 

 southern limits undetermined. 317 specimens collected. 



Shell (fig. xii-F) : smaller and slightly thinner and more 

 slender than muskusi. Color: spiral bands absent or present, 

 rarely several continuous bands, frequently broken spirals, but 

 most commonly with blotches of color connected to form un- 

 dulating bands parallel to the growth lines ; eroded apex and 

 apical plug usually whitish or light yellow, and rarely as dark 

 as normal muskusi. Sculpture of last whorl (fig. x-32) : 

 growth-costae much lower, and more closely-spaced (appar- 

 ently due to the development of the interstitial cords) than in 

 muskusi; spiral sculpture typically almost as prominent on the 



