SUCCINBA. 41 



much more flexuose, and the upper third of the shell be- 

 comes gradually attenuated, so as to give a sharp pointed 

 appearance, though the spire itself is short. The revolving 

 lines are sometimes continuous over the whole body whorl, 

 but generally interrupted, or confined to the interstices of 

 the incremental striae or wrinkles. It shares this peculiar- 

 ity with S. concordialis Gould, and S. lineata nob. 



Named in honor of Dr. F. V. Hayden, the discoverer of 

 the species. 



SUCCINE A LUTEOLA GOULD vol. ii. p. 75, pi. Ixvii. c. fig. 1. 



Succinea luteola PFEIFFER, Mon. Hel. Viv. iii. 16. 



Texasiana PFEIFFER, 1. c. vol. ii. p. 526 ; vol. iii. p. 17 ; in Roemer's 



Texas, p. 456. 

 CHEMNITZ, ed. 2, p. 42; pi. iv. f. 21-23, (1854). 



PfeifTer (Sept. 1857) writes " My Succinea Texasiana is 

 a synonym of luteola Gould. 



SUCCINEA CONCORDIALIS GOULD vol. ii. p. 82, pi. Ixvii. a. fig. 2. 



Succinea concordialis PFEIFFER, Mon. Hel. Viv. iii. p. 16. 

 munita BINNEY, vol. i. 



SUCCINEA EFFUSA SHUTTLEWORTH. 

 PLATE LXXX. FIGURE 12. 



T. depresso-ovata, tenuissima, striatula, parum nitens, diapliana, griseo- 

 cornea ; spira brevissima, acuta ; anfr. 2, ultimus magnus, depressus, 5-6 

 longitudinis aequans, columella vix arcuata, subrecedens ; apertura ampla, 

 obliqua, ovalis ; perist. simplex, regulariter arcuatum, basi non incum- 

 bens. (Pfr.) 



SYNONYMS AND REFERENCES. 



Succinea effusa SHUTTLEWORTH, mss. 



PFEIFFER, Mon. Hel. Viv. iii. p. 17. 

 CHEMNITZ, ed. 2, p. 42, pi. iv. fig. 18-20, (1854). 



DESCRIPTION. 



Animal not observed. 



Shell depressed-oval, very thin, transparent and shining, 

 lightly striated, grayish horn-colored; spire remarkably 



6 



