102 THE NAUTILUS. 



advertence. Amoeroecium is a genus of compound Ascidians. Ver- 

 rill, in his Rep. on Invert, of Vin. Sound, 1873. notices (on different 

 pages) both Amoeroecium pallidum and Onchidoris pallida which 

 latter is of course what Mr. Lermond intended to cite. 



Pallida is, however, a synonym of LameUidoris aspera (A. & H.). 

 The entry, therefore, should stand as LameUidoris aspera (A. & H.) 

 with Proctaporia fusca Stimps. 1860, Doris pallida Ag. 1849, and 

 Onchidoris pallida " Verrill," Vei-rill 1870 and 1873, in synonymy. 



LameUidoris muricatus should be written muricata. 



Palio lessoni should be written lessonii. 



UNIONID^ FBOU SOUTHEASTEBN ABEANSAS AND N. £. LOUISIANA. 



BY E. G. VANATTA. 



Mr. Chtrence B. Moore collected the following species of Unionida 

 while on an archaeological expedition during the winter of 1908-09. 



Quadrula ebena Lea was everywhere tlie most abundant species. 

 Dr. Pilsbry agrees with me in considering Unio dombeyana Val. in 

 Humboldt et Bonpland, Rec. Obs. Zool., 1833, Vol. 2. p. 227, pi. 

 53, f. 1, a valid variety of Quadrula heros Say, instead of a synonym 

 of Q. trapezoides Lea. 



The originally varietal name ohesa Simps, is used instead of 

 Tritogonia tuberculata Bar. as the name tuherculata is preoccupied in 

 Quadrula. Cnto iwierctt/a^MS Barnes was grouped with U. apiculatus 

 (now referred to the genus Quadrula) by Pilsbry in 1891 (Nau- 

 tilus V, p. 76) ; a position confirmed by Dr. H. von Ihering in 

 1901 (Nautilus XV, p. 39), and by Dr. Arnold Ortmann this 

 year. (Ann. Carnegie Mus., 1909, Vol. 5, p. 193.) 



All the specimens of Quadrula trapezoides, pyramidata, ebe7ia, 

 obesa and Plagiola securis were smaller than the usual size. 



I. Pyles Landing, Ouachita River, Calhoun Co., Arkansas. 

 Obovaria castanea Lea and Anodonta opaca Lea. 



IL Near Pigeon Hill, Ouachita River, Union Co., Arkansas. 

 Obovaria castanea Lea. Quadrula plicata Say. 



Plagiola securis Lea. " heros dombeyana Val. 



" elegans Lea. " mefanevra Raf. 



Strophitus edenfulus Lea. " asperrima Lea. 



Unio subgibbosus Lea. " obesa Simps. 



