U N I . 



Plate LVII. 



Species 388. (Mus. Tavlor.) 



Unio delodontus. Un. testa ovatd, crmsa, iiimichi, l(v- 

 viyatd, coiicentrice dktaider rugutd, epldermide oli- 

 vawo-fuscd indutd, intiis opacd, laded; latere podico 

 elongato, lata, arcuatim angulato, area podancjulari 

 angmtd, hiarg'me dornali vix declivi, ligamento luagiio, 

 termino subacuminato, margiiie ventrali arjualUer con- 

 vexo ; latere antico bred, margiiie dorsali antice siib- 

 ciineatu, termino roliiiidu, iimboidbus lacibiis. 



The conspicuous-toothed Unio. Shell ovate, thick, 

 tumid, sniooth, eoncentrically distantly wrinkled, 

 covered witli an olive-bi'own epidermis, opake, white 

 within ; posterior side elongated, wide, with an 

 arched angle, postangular area naiTOw, dorsal margin 

 scarcely sloping, with large ligament, end subacumi- 

 nated, ventral margin equally convex ; anterior side 

 short, with dorsal margin anteriorly subcuneate, end 

 rounded, uraboes smooth. 



Lamakck, Anim. sans vert. 

 Unio lacleoliix, Lea. 



[lab. La Plata. 



One of the most ponderous species, of oval form. 



Species 289. (Mus. Taylor.) 



Unio magnieicus. Un. testa compressd, teuuissiind, ova- 

 td, laid, si/inphj/notd, lavi, viridi conceutrice fasci- 

 aid, fasciiis viridibus, latis, subdivisis radiatd; latere 

 jjostico oblongo, expanso, margine dorsali recto, sub- 

 alato, margine laterali obliquo, termino truncate, mar- 

 gine ventrali prope terminum valde sursuin acclivi, 

 ■medio producto, antice siibcontracto, ad terminum an- 

 iicum elemto ; latere antico angusto, superne divari- 

 catim sulcato, margine dorsali recto, umhonibus coiii- 

 pri'ssis, undulatim. rugosis, dentibus lateralibus ten/ii- 

 lius, lamiuatis, dentibus cardinalibus nullis. 



Tub magnificent Unio. Shell compressed, very thin, 

 ovate, wide, symphynote, smooth, concentrically 

 banded with green, rayed with broad green subdi- 

 vided bands ; posterior side oblong, expanded, dorsal 

 margin straight, subalate, lateral margin oblique, 

 end truncated, ventral margin much sloped upwards 

 towards the end, produced in the middle, subcon- 

 tracted in front, elevated at the anterior extremity ; 

 anterior side narrow, divergently sulcated above, dor- 



sal margin straight, unil)oes compressed, undulately 

 rugose, lateral teetli thin, laminar, cardinal teeth 

 none. 



Lea, Obs. on Unio, vol. i. p. I.j5. pi. ."). f. Ik 



Hab. China. 



Notwithstanding the general appearance of this shell 



and the thinness of tlie lateral teeth, it may yet be classed 



witli otlier alate species in the genus Unirj. 



Species 390. (Mus. Taylor.) 



Unio FUNEBRALIS. Un. trsld rolnndo-snhtrigond, ralilr 

 inirqnilaterali, cra-ssd (antice pracipue), epiderniidi- 

 iiiijrd, striata, validd indutd, intus albo-subpurpnred, 

 olimcen-nebulatd ; latere postico tumido, expanso, ra- 

 didtim impresso, margine dorsali arcuatim elevato, 

 area compressd cuneatd radiato, margine laterali ro- 

 tn/tdo, margine ventrali medio recliusculo ; latere antico 

 breBistimo, siiperni ennento. depresso, umbonibus subter- 

 miniilibns hand jirominentibus, dentibus laternlibus 

 elongalis, cardinalibus magnis laceratis. 

 The mourning Unio. Shell rounded-subtrigonal, very 

 inequilateral, thick (principally in front), covered 

 with a black striated solid epidermis, purplish-white 

 clouded with olive inside ; posterior side tumid, ex- 

 panded, radiately impressed, dorsal margin elevated 

 in an arch, rayed with a compressed cuneate area, 

 lateral margin rounded, ventral margin rather straight 

 in the middle; anterior side very short, cuneate above, 

 depi'essed, umboes subterminal, not prominent, lateral 

 teeth long, cardinal teeth large, jagged. 

 Lea, Obs. on Unio, vol. x. p. 14. pi. 41. f. 2SG. 



Unio nociurnis, Lea. 

 Hab. Uruguay, South America. 



The specimen bere figured is evidently older than either 

 of those representing the two species in Lea's work ; it is 

 in consequence less smoothly and evenly rounded. Be- 

 tween Mr. Lea's two shells I do not think the diiferences 

 of specific importance. 



Species 291. (Mus. Taylor.) 



Unio Tampicoensis. Un. testd snbfrapezoided, tumidd, 

 crassd, lavigald, epidermide validd subpolild niyrd 

 iuduld, intus violaced; latere postico sub/juadrato, 



September, IbO^ 



