Subfamilies, Genera, and Suhgeiiera — Recent and Fossil 133 



Radula (plate 64). In scalare, the center tooth (figs. 1, 89) is ahiiost 

 twice as wide at the base as at the summit of the reflection, the two broadly 

 aculeate cusps of which reach the lower margin of the base of attachment. 

 The lateral teeth (1-8) are about as broad as high and the reflection, 

 which is tricuspid, extends below the base of attachment. The mesocone is 

 roundly blunt, the entocone and ectocone broadly aculeate. The inter- 

 mediate teeth (9-11) have the mesocone as in the lateral teeth, but nar- 

 rower, the entocone as in the laterals. On the eleventh tooth, the entocone 

 is split into two short, aculeate cusps. The ectocone in all intermediate 

 teeth is split into two sharp cusps. The marginal teeth (12-21) are very 

 long and narrow and claw-like. The mesocone is aculeate in all teeth but 

 is always distinct. The entocone becomes very wide and is split into from 

 four to seven small cusps. The ectoconic region on the outer margin of the 

 tooth bears three very small cusps. 



In another specimen from the same locality, the teeth are somewhat 

 smaller (fig. 2). In H. duryi normale, from the Tamiami Trail (fig. 3), the 

 teeth are all narrower than those of scalare, although the shell is much 

 larger. The two cusps of the center tooth do not reach the lower margin 

 of the base of attachment. The laterals (1-11) and the intermediate 

 tooth (12) are narrow but the cuspidation is the same as in scalare. The 

 marginal teeth (13-29) are similar to those of scalare differing only in 

 being somewhat narrower. In a specimen from Paines Prairie (fig. 4), the 

 teeth are more like those of scalare. Two rows are figured, the 55th and 

 the 140th. The number of intermediate teeth is smaller in normale than in 

 scalare. The figures on plate 64 agree with those published bv Pilsbrv 

 (1934, p. 34, fig. la). 



The formula for scalare is 27-1-27 to 29-1-29 and there are 160 to 190 

 rows of teeth. Pilsbry gives 33-1-33 as the formula ( 1934, p. 35) . A number 

 of membranes were examined but none gave the larger formula. The outer 

 teeth are small and vestigial. 



The formula of normale from the Tamiami Trail is 28-1-28 to 31-1-31 

 with 175 rows of teeth. In specimens from High Springs several radulae 

 gave 27-1-27 as the formula. These specimens vary toward the race inter- 

 calare. From Paines Prairie, several membranes gave 28-1-28 and 29-1-29 

 with 165 rows of teeth. H. d. eudiscus from Silver Springs gave a formula 

 of 27-1-27 to 28-1-28 with 154 rows of teeth. The variation in formulae is 

 from 27-1-27 to 31-1-31 for the complex of duryi and to 33-1-33 for 

 scalare as examined by Pilsbry. 



For the anatomical data herein presented thirty-five specimens have 

 been examined from the following localities, all in Florida: 



Helisoma scalare 



Lake Butler. Collected by Dr. E. A. Andrews of the Johns Hopkins University 

 Helisoma duryi normale 



Tamiami Trail, 40 miles west of Miami. Collected by Paul P. McGinty, Boynton, 



Florida 

 Canal west of Boynton, Palm Beach County. Collected by Paul P. McGinty, 



Boynton, Florida 

 Bridge No. 32, on canal west of Miami. Collected by W. F. Shay, St. Louis, 



Missouri 

 Paines Prairie, near Gainsville. Collected by T. van Hyning, Florida State 



Museum 

 Santa Fe River, High Springs. Collected by T. van Hyning 



