l'.lltil 



NATURAL SCIENCES OF PHILADELPHIA. 



347 



The lower third of the spermatheca duct is Large, then abruptly 

 contracting. There is a general similarity with the genitalia of 

 0. s. depressa. Measurements in mm. follow. Length of penis 12, 

 of its costate lower portion 4; epiphallus 4.5; penial retractor 4; 

 vagina 4; spermatheca and duct 10.5; diam. of shell 16 mm. 



The three areas of the radula appear distinct, in a slightly enlarged 

 view, the rows of marginal teeth being oblique. In most Oreohelices 

 the areas are not well marked. The central tooth and laterals have 

 rudimentary side cusps. Formula 16, 12, 1, 12, 16. Text fig. 16. 

 By the forms of the individual teeth and the more distinct differen- 

 tiation of areas in the radula, this species differs from the strigosa 

 series. 



Oreohelix haydeni (Gabb). PI. 21, figs. 1. 2, 4, 8. 



0. haydeni does not differ from 0. strigosa depressa in any important 

 or diagnostic characters of the genitalia or dentition, but the features 

 of the shell seem quite sufficient to give it specific rank. 



The typical form, from Weber Canyon in the Wasatch Range, 

 has not been collected alive so far as I know. The forms examined 

 agree pretty closely in soft anatomy. The internally costate part 

 of the penis is about one-third of the total length. The distal 

 portion collapses flat. The penial retractor is decidedly shorter in 

 subsp. corrugata and hybrida than in subsp. betheli and gabbiana. 

 This is probably not a character of much importance. The retractor 

 is sometimes continued in the lung floor for some distance, as in 

 pi. 21, figs. 2 and 8. Only the free part is measured in the table. 

 In hybrida the penis is more twisted than in the other forms, at least 

 in the individual dissected. In all the forms, the distal part of the 

 penis collapses more or less flat. 0. h. betheli has four unequal ribs 

 in the lower part. 



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