HISPANIOLAN AND BAHAMAN ANNULARIIDAE 237 



a conspicuously reflected auricle at the posterior angle, which is rendered 

 somewhat irregular by the reflected breathing siphon ; the inner peristome 

 is moderately exserted and slightly expanded. Operculum typically opis- 

 thosiphonid. 



This species occupies several of the cays forming the Ragged Island 

 Chain. I am recognizing the following subspecies : 



KEY TO THE SUBSPECIES OF OPISTHOSIPHON (OPISTHOSIPHON) 

 PHOENICOPTERUS 



Axial and spiral sculpture strong phoenicopterus 



Axial and spiral sculpture not strong nutricius 



OPISTHOSIPHON (OPISTHOSIPHON) PHOENICOPTERUS PHOENICOPTEBUS, 



new subspecies 



Plate 37, Figure 10 



This subspecies comes from Flamingo Cay and is easily distinguished 

 from Opisthosiphon (Opisthosiphon) phoenicopterus nutricius by its 

 much stronger axial and spiral sculpture. The type has 52 axial ribs on 

 the first, 70 on the second, and 78 on the last of the remaining turns. 

 The spiral sculpture consists of rather strong threads equaling the rib- 

 lets in strength. Of these 8 occur on the first, 10 on the second, and 13 

 on the last between the summit and suture. The combination of the two 

 elements gives to the whorls a somewhat fenestrated pattern. There are 

 five spiral threads on the base and umbilical wall. 



The type (U.S.N.M. No. 127467) was received from the Bland Col- 

 lection and comes from Flamingo Cay. It has 4 whorls and measures: 

 Length, 9.3 mm. ; greater diameter, 5.5 mm. ; lesser diameter, 4.4 mm. 



OPISTHOSIPHON (OPISTHOSIPHON) PHOENICOPTERUS NUTRICIUS, 



new subspecies 



Plate 27, Figure 13 



This subspecies I collected on Nurse Cay, on Knife Cay, and on an 

 unnamed cay west of Frog Cay in the Ragged Island Chain of islands. 

 The feeble axial and spiral sculpture will readily distinguish this from 

 Opisthosiphon (Opisthosiphon) phoenicopterus phoenicopterus. The 

 type has 45 axial riblets on first, 62 on the second, 69 on the third, and 

 67 on the last nine-tenths of the remaining turns. Of spiral threads the 

 first whorl has 8, the second 11, the rest 13 between summit and suture. 

 There are six spiral threads on the base and four on the umbilical wall. 



The type (U.S.N.M. No. 391572) comes from Nurse Cay. It has 3.9 

 whorls remaining and measures: Length, 9.1 inm. ; greater diameter, 

 5.2 mm. ; lesser diameter, 4.5 mm. 



U.S.N.M. No. 391332 contains 5 specimens from Knife Cay, and U,S, 

 N.M. No. 390237 consists of 3 from an unnamed cay west of Frog Cay. 



