SYNONYMIC EEFERENCES. 37 



Present rererence. 



Billingsella? appalachia Walcott [1905a, p. 231] Billingsella? appalachia. 



Billingsella billingsi Schuchert [1897, p. 158] Protorthis billingsi. 



(Billingsella) billingsi [Protorthis], Grabau and Shimer [1907, p. 211] Do. 



Billingsella bivia Walcott [new] Billingsella bivia. 



Billingsella circe Walcott [1901, p. 673] - Quebecia circe. 



Billingsella coloradoensis Grabau and Shimer [1907, p. 210] Billingsella coloradoensis. 



Schuchert [1897, p. 158] Do. 



Walcott [1899, pp. 450-451] Do. 



Walcott [1905a, pp. 231-234] Do. 



Billingsella dice Walcott [1905a, p. 234] Billingsella dice. 



Billingsella exporrecta Walcott [1905a, pp. 234-236] Billingsella exporrecta. 



Billingsella exporrecta rugosicostata Walcott [1905a, p . 236] Billingsella exporrecta rugosicostata. 



Billingsella festinata Hall and Clarke [1892c, p. 230] Nisusia festinata. 



Billingsella hai'lanensis Walcott [1905a, p. 236] Wimanella harlanensis. 



Billingsella hicksi Walcott [1905a, p. 237] Billingsella hicksi. 



Billingsella highlandensis Walcott [1905a, pp. 237-238] Billingsella highlandensis. 



Billingsella lindstromi Walcott [1905a, pp. 238-239] Billingsella lindstromi. 



Billingsella major Walcott [1905a, p. 239] Billingsella major. 



Walcott [1908d, p. 101] Do. 



Billingsella marion Walcott [1908d, p. 102] Billingsella marion. 



Billingsella obscura Walcott [1905a, p. 239] Billingsella obscura. 



Billingsella orientalis Hall and Clarke [1892c, p. 230] Billingsella orientalis. 



Walcott [1905a, pp. 239-240] Do. 



Billingsella pepina Hall and Clarke [1892a, PL VIII, figs. 1 and 2] Billingsella coloradoensis. 



Hall and Clarke [1892c, p. 230] Do. 



(Billingsella) pepina [Orthis], Sardeson [1896, p. 96] Do. 



Billingsella plicatella Walcott [1905a, pp. 240-241] Billingsella plicatella. 



Billingsella pumpellyi Walcott [1905a, p. 242] Billingsella pumpellyi. 



Billingsella quacoensis Schuchert [1897, p. 159] .Protorthis quacoensis. 



Billingsella retroflexa Matthew [1903, pp. 148-151] Billingsella retroflexa. 



Billingsella richthofeni Walcott [1905a, pp. 242-243] Billingsella richthofeni. 



Billingsella romingeri Walcott [1905a, pp. 243-244] Billingsella romingeri. 



Billingsella saff ordi Walcott [1905a, p . 244] Wimanella saff ordi . 



Billingsella salemensis Walcott [1905a, p. 245] Billingsella salemensis. 



Billingsella striata Walcott [1905a, p. 245] Billingsella striata. 



Billingsella whitfieldi Schuchert [1897, p. 159] Billingsella wMtfieldi. 



Walcott [1905a, p. 246] Do. 



Billingsella (Otusia) Walcott [1905a, p. 246] Otusia. 



Billingsella (Otusia) sandbergi Walcott [1905a, pp. 246-247] Otusia sandbergi. 



billingsi [Billingsella], Schuchert [1897, p. 158] Protorthis billingsi. 



bilHngsi [Orthis], Hartt [1868, pp. 644-645] Do. 



Hartt [1878, pp. 644-645] ' Do. 



Hartt [1891, pp. 644-645] Do. 



Matthew [1886, p. 43] Do. 



Walcott [1884a, pp. 17-18] Do. 



billingsi [Orthis (Protorthis)], Wysogorski [1900, p. 227] Do. 



bilKngsi [Orthisina?], Matthew [1891, p. 131] Do. 



billingsi [Protorthis], Hall and Clarke [1892a, p. 274] Do. 



Hall and Clarke [1892c, pp. 219 and 232] Do. 



Walcott [1905a, pp. 281-282] Do. 



billingsi [Protorthis (Billingsella)], Grabau and Shimer [1907, p. 211] Do. 



billingsi [Syntrophia], Walcott [1905a, pp. 291-292] Huenella billingsi. 



BilUngsia Ford [1886a, pp. 466-467] Elkania. 



de Koninck [1876] Does not equal Elkania. 



Walcott [1886, pp. 5, 21, 60, and 62] A genus of the Gastropoda. 



Billingsia? ambigua Ford [1886a, p. 467] Elkania ambigua. 



Billingsia desiderata Ford [1886a, pp. 466 and 467] Elkania desiderata. 



Billingsia? ida Ford [1886a, p. 467] Elkania ida. 



Billingsia pretiosa Ford [1886a, p. 467] Acrothele pretiosa. 



billingsiana [Lingula], Whiteaves [1878, p. 226] Lingulella billingsiana. 



billingsiana [Lingula cf.], Matthew [1894, p. 93] Lingulella grandis. 



bisecta [Acrotreta], Matthew [1901a, pp. 275-276] Acrotreta bisecta. 



Matthew [1902b, p. 394] Do. 



Matthew [1903, pp. 186-187] Do. 



