UNIO.— Plate LXXIV. 



auhventricosa, sMavii/atd, luteo-oUvaceu, lineli nigro- 

 viridibus obscuris multis superne radiatd ; margine 

 ventrali subrecto ; area posticd extremd laid ; coda 

 umbonali eonspieud ; lunula nulla ; margarUd albd ; 

 dentlbus cardinalibus valde lacinialu, pgramidalibus. 



The Oregon Unio. Shell strong, elongatnd suhoval, 

 not particularly inequilateral, very bhintly subbi- 

 angulated behind, subventricose, nearly smootii, dull 

 olivaceous yellow, painted above with numerous ob- 

 scure radiating lines of dusky green ; ventral margin 

 scarcely indented ; uiubonal area broad ; the ridge dis- 

 tinct ; no lunula ; nacre white ; cardinal teeth much 

 jagged, pyramidal. 



Lea, Obs. on Unio, vol. v. p, 31. pi. 2J. f. 33. 



IJnh. Columbia river, Oregon. 



The painted lines are more densely disposed towards 



the ligament. 



Species 3S-1. (Mns. Hanley.) 

 I'nio GLEIiUms. Un. Icsid sails parvd, solidd, veidri- 

 cosd, rotundato-ovali, vise iueequilaleraU, fiamdo-oU- 

 vaceS, sublavigald ; margine dorsali subarcualo, vix 

 decUvi, utrinque angulato ; margine venlrali arcualo, 

 utrinque (el antlce pra'serlim) accUvi; ualibus latius- 

 cnlis, depressis ; lunuld angustd ; margarild albido- 

 rubescenle, niiidissimd ; dentibus cardinalibus solidis, 

 valde laciniatis, haud laminatis ; dentibus lateralibus 

 arcuatis. 

 The little clod Unio. Shell rather small, solid, ven- 

 tricose, rounded-oval, not so very inequilateral, yel- 

 lowish olive, nearly smooth ; dorsal margin curved, 

 yet scarcely sloping, angulated at each extremity ; 

 ventral margin arched, rising at both ends, but espe- 

 cially in front ; beaks rather broad, depressed; lunule 

 narrow; nacre silvery, white with a pinkish cast, very 

 iridescent; cardinal teeth nmch jagged, solid, not 

 lamellar ; lateral teeth curved. 

 S.\Y, Amer. Conch, pi. 34. 

 Unio subglobosus. Lea. 

 JIab. Bayou Teche, Louisiana, N. America. 



This is stated by Lea to be the U. rotundalus of La- 

 marck, which no one would surmise from the description. 

 Its nmbonal ridge is well marked, the succeeding area de- 

 cidedly narrow. 



Species 3S.5. (JLis. Hanley.) 



Unto calamitarum. Vh. IvsUi pan-il, ralida, ovali- 

 snbreniformi, antice brevi, cotnpressiusculd,fusco-oU- 

 vaccd, superiw confertim. el cuncentrici corrugatd ; 

 margine dors'i/i aiitiro di'clivi, margine vevfrali in- 

 ciirniln ; iialiliii\ iirnti^,viilik iiic/iiKitis ; limiild magna, 

 priifiiiidii ; inargiirild sqiiaVide albd ; di/iitibiis cardina- 

 libus viagnis, validis, hand Ira/iwer.iis ; dentibus late- 

 ralibus arcuatis. 



The reed-dwelling Unio. Shell small, strong, oval- 

 subreniform, short in front, rather compressed, dusky 

 olive, densely wrinkled concentrically near the beaks ; 

 front dorsal edge sloping ; ventral margin incurved ; 

 beaks acute, much inclined ; lunule large, profound ; 

 nacre dirty white, cardinal teeth large, strong, not 

 transverse, lateral teeth curved. 



Morelet, Testae. Nov. vol. i. p. 30. 



Hab. Bahmtie, near Palenque. 



The imperfect state of specimens renders a more com- 

 plete description impossible. The hinder extremity is 

 rather broad. 



Species 386. (Mus. Haidey.) 



Unio lutllentus. Un. testa tenui, compressimmu, 

 luteo-oUvaced, hand radiatd, sublavigatd ; area pos- 

 ticd extremd lata, rugis divergentibus brevibus remotis 

 .sparsim sculptd ; margine dorsali postice accUvi, con- 

 vexiusculo ; margine ventrali vix subretuso, natibus 

 hnud eminentibus ; margaritd squalidi albidd; dentibus 

 cardinalibus laminatis. 



The muddy Unio. Shell thin, much compressed, of a 

 yellowish olive-green, not rayed, nearly smooth, with 

 a few distant obscure, short, divergent corrugations 

 on the broad umbonal slope ; hinder dorsal edge 

 somewhat curved and elevated ; ventral margin 

 scarcely retuse ; beaks not prominent ; nacre dirty 

 white ; cardinal teeth laminar. 



Gould, Proc. Boston Soc. N. H. vol. iii. p. 295. 



Hub. New Zealand. 



The umbonal ridge is not elevated. Tlie nacre is 

 usually more or less stained in the umbonal cavity. 



