164 The Molluscan Family Planorhidae 



and is enlarged just behind the buccal sac. The salivary glands form a 

 loop. The buccal sac is short, high and pyriform, as in Carinifex. 



The jaws are three in number, differing markedly from the single horse- 

 shoe-shaped jaw of Carinifex. The superior jaw is low and about three 

 times as wide as high. The side jaws are as in Helisoma. The face of the 

 superior jaw is striated vertically. There is little difference between the 

 jaws of klamathensis and diagonalis. Dall says there are no accessory 

 plates (side jaws) but they occurred in all specimens personally examined. 

 The jaw figured by Dall (his plate 2, fig. 11a) is different from the jaws 

 found in the two races examined. 



The radula of P. effusa klniitathoi.'iis (plate 65, fig. 3) has a squarish 

 center tooth, the bicuspid reflection not reaching the lower margin of the 

 base of attachment. The lateral teeth (1-8) are scjuarish and tricusi)id, all 

 cusps being sharp and spade-shaped. The intermediate teeth (9-11) are 

 narrow, the ectocone splitting into two sharp cusps as long as, or nearly 

 as long as, the mesocone. There are two small cusps on the outer border 

 of the tooth, above the ectocone. The marginal teeth (13-15) are narrow, 

 the entocone with four to five small cusps, the ectoconic region with three 

 cusps. The outer marginal teeth (16-19) are very narrow and are simply 

 serrated on the ectoconic side, there being no division into entocone, meso- 

 cone, and ectocone. Ball's figure of the radula of solida (his plate 2, fig. 9) 

 shows the lateral teeth with a rounded mesocone and all cusps appear too 

 blunt. The marginal teeth are too wide and the small cus])s are not shown. 



Radula Formulae of Paraphnhjx 



Species Formula Locality Roirs Collector 



klamathensis 19-1-19 Klamath Lake, Oregon 125 J. Henderson 



diagojialis 21-1-21 Crater Lake, Oregon 100-114 J. Henderson 



solida 22-1-22 White Pine, Nevada 150 Ball's paper 



The following material has been examined for the anatomical data 

 contained in this work. P. effusa klamathensis from outlet of Upper 

 Klamath Lake, Oregon, eight si)ecimens examined. P. effusa diagonalis from 

 Crater Lake, Oregon, eight specimens examined. Both lots collected by 

 J. Henderson. 



Geographical Distribution. Parapholyx is purely an American genus 

 confined to the west coast of America from Washington southward to Cali- 

 fornia and eastward to Nevada. Pompholyx leana H. and A. Adams was 

 described from 'West Columbia,' but no specimen of this genus has been 

 seen from British Columbia and it is very doubtful that the genus is found 

 north of the United States. A number of species and races have been 

 described and the same opinion expressed for the division of Carinifex may 

 also ap]^ly to this genus. 



Species Considered as Valid. 



Parapholyx ejjusa effusa (Lea) Parapholyx nevadensis J. Henderson 



Parapholyx ejjusa coHata (Hemphill) Parapholyx mailliardi Hanna 



Parapholyx ejfusa diagonalis Parapholyx solida solida (Dall) 



J. Henderson Parapholyx solida optima (Pilsbry) 



Parapholyx ejfusa klamathensis F. C. Parapholyx leana (H. and A. Adams) 



Baker Species practically unknown 



Geological Distribution. Parapholyx is certainly known from the 

 Pliocene to the Recent fauna. It may occur in earlier deposits. One extinct 



