820 PIIOCEEDINGS OF THE NATIONAL MUSEUM. vol. xxii. 



" Margaron {Unio) oricntalis Lea, Syu., 1852, p. 38; 1870, p. 61. 



^ Unio procVxctns MoussoN, L. und S. W. Moll. Java, 1849, p. 93, pi. xvir, figs. 



3-5; Zeits. fiir Mai., VII, 1851, p. 46. - 

 " UniojroclHctior Lea, Syu., 1852, p. 29.— ** vox Martens, Mai. B1.,X1V, 1866, p. 



IC—'II. :md A. Adams, Gen. Eec. Moll., II, 1857, p. 494. 



Java. 



Section RAEIATXILA, Simpson, 

 (Type, Unio (ri>ipisiilcaii(s lienson.) 



Shell rather solid, triangular oval, with high beaks which are but 

 little inflated, not very full at post base, bluntly pointed behind, the 

 beaks and entire surface covered with radiating, occasionally slightly 

 zigzag or divaricate ridges which are cut more or less into nodules 

 or cancellations by concentric sulcations, the sculpture of the posterior 

 slope stronger, and curving upward 5 pseudocardinals of the left valve 

 2 to 3, ragged, the anterior larger, two in the right valve, with a 

 parallel sided socket, tlie larger teeth compressed but ratlier solid. ^ 



jNODULARIA CRISPISULCATA Benson. 



^ Unio crispisuJcaivs Lea, Ann. aud Mag., X, 1862, p. 193. — ■' Sowerby, Conch. 

 Icon., XVI, 1866, pi. xlix, fig. 262. — ^IIaxley and Theobald, Conch. Ind., 

 1876, p. 6., pi. XI, fig. 5.— *P.ETEL, Conch. Sam., Ill, 1890, p. 149. 



"Margaron {Unio) crisplsulcaius Lea, Syn., 1870, p. 31. 



Burma. 



NODULARIA LIMA Simpson. 



* Unio radiila Benson,^ in Hauley, Biv. Shells, Supp., 1856, p. 382. — *IIanley 

 and Theobald, Conch. Ind., 1876, p. 5, pi. x, fig. 3. — * P/ETEl, Conch. Sam., 

 Ill, 1890, p. 165. 



" Di/snomia raclula Rochebruke, Bull. Soc. Phil., VI, 1882, y. 42. 



Assam; Cambodia. 



Section C^LATURA Conrad, 1853, 

 (Type, Z7«io cegypiiacus Cailliaud.) 



Shell elliptical, pointed or rounded behind, usually slightly produced 

 at the post base; beak sculpture consisting of zigzag ridges which are 

 generally quite i^ustulous, the sculpture often extending on to the usu- 

 ally rayed disk; teeth compressed; pseudocardinals lamellar. 



Animal described under Nodularia. (See page 806.) 



(Group of Nodularia wgyptiaca.) 

 Characters the same as of the section. 



' Notwithstanding the considerable difference between this group and all other 

 Nodularias there are species such as occatus, which seem to stand between it aud the 

 caruleus groui>, and show the relatiouship of the two, 



"The name radula was tised by Say for a Unio in 182,'. 1 change Benson's name as 

 above. I am not positive as to the relatiouship of this species. 



