FLEMINGER and HULSEMANN: FOUR SIBLING SPECIES OF PONTELLINA 



Throckmorton and Voris show empirically 

 that characters are decidedly not equal in their 

 content of phylogenetic information. Their 

 operational method for character selection rests 

 upon the direct and assumption-free advantages 

 of a posteriori weighting of correlated sets of 

 derived characters. 



Judging from the numerous articles in 

 Systematic Zoology, numerical taxonomic 

 phylogenies derived from large numbers of 

 unweighted characters do not vary from phylo- 

 genies implicitly or explicitly arranged by 

 experienced workers employing sets of corre- 

 lated adaptive characters. 



Body Dimensions and Proportions 

 Total Length (TL) 



Intraspecific sexual differences in TL are 

 greater than interspecific differences; males are 

 about 10% shorter than females (Table 6, Figure 

 23). In both sexes morii and .so6?'/»fl are smaller 

 than platychela and plumata. The diffei'ence 

 between the mean TL of males or females of 

 species belonging to the same pair is not signifi- 

 cant. However, the difference between the mean 

 TL of either species of one pair with that of 

 either species in the other pair is highly signifi- 

 cant in both sexes (Student's f-test). The over- 

 all difference is produced largely by the dis- 

 tance between the rostrum and the cephalic 

 groove and the length of the furca (see below). 



Prosome-Urosome Length Ratio (PUR) 



In both sexes niorii and sobrina occur at the 

 high end of the PUR distribution (Table 6. 

 Figure 24). In males, morii and sobri)m have 

 similar distributions at the high end of the 



25% 



> 

 o 



-z. 



uj 



o 



UJ 



"^ 25% 

 U- 



75% 



25% 



-25% 



25% - 



25% 



25% 



-25% 



12 14 1.6 18 



TOTAL LENGTH, mm 



O^ N = 57 

 platychela 



% N -30 



O^N = 67 

 plumata 



N = 75 



¥ 



(T^N = 58 

 morii 



% N = 54 



O^N = 56 

 sobrina 



% N= 50 



2.0 



Figure 23. — Frequency distribution of total length for 

 both sexes of the four species of Pontellina. 



Table 6. — Total length (TL) and prosome-urosome length ratio (PUR) of Pontellina spp. adults; data from various 



geographical localities combined. 



Species 



TL (mm) 



PUR 



Moles: 



P. platychela 

 P. plumata 

 P. morii 

 P. sobrina 



Females: 



P. platychela 

 P. plumata 

 P. morii 

 P. sobrina 



95 



