92 University of 3Iichigan 



Shell (fig. xvii-68) : considerably smaller and much thinner 

 and more polished and translucent than raveni. Growth- 

 riblets of later whorls much lower, more rounded, and more 

 widely spaced. Aperture relatively larger. Otherwise as in 

 raveni. 



Measurements 

 Shell Spire Aperture "Whorls 



alt. maj. diam. maj. diam. alt. diam. 



C2, type 



(fig. 68) 7.75 30(2.32) 26(2.00) 18(1.38) 108(1.49) I31/2 

 C2, largest 7.76 28(2.84) 28(2.19) 23(1.77) 103(1.83) 8 



The several hundred specimens collected from the type 

 locality are all quite distinct from typical raveni, but they do 

 intergrade slightly with those from near New Port (CI), 

 which are connected by intermediates with those from the more 

 northern localities. With equal reason, these two subspecies 

 could be considered as separate species which produce hybrids 

 at their point of contact. 



Brachypodella raveni knipensis, new subspecies 



Type locality: (C17a) Seroe Djerimi, northern Curasao. 



Distribution: Curasao; north of Seroe di Boca (at least 

 C15, 17, 20). 



Shell (fig. xvii-69) : averages considerably smaller than 

 raveni; greatest diameter at about the 3rd whorl above the 

 aperture. Carina and peripheral emargination carried higher 

 on the whorls. Growth-riblets of later whorls more widely 

 spaced and slightly heavier. Otherwise as in raveni. 



Measurements 

 Shell Spire Aperture Whorls 



alt. maj. dia,m. maj. diam. alt. diam. 



C17, type 



(fig. 69) 7.97 30(2.39) 26(2.05) 16(1.27) 118(1.50) ISV2 

 C17, largest 7.24 36(2.61) 29(2.10) 21(1.51) 107(1.61) 8 



