298 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



ACANTUOIDEA. 



Solei'ochiton, Francma, DinopJax, Daivsonia, Beania, and Arthuria not examined. 

 Acanthopleura Cpr. ex Guilding. 



A. Hpinigera Sby, (Type.) Minor lateral large, shaft long, cusped, wings long,^ 

 narrow, linguiform; major lateral with a simple rounded cusp, shaft keeled, keel 

 with a cuspidate process; inner uncini nodulose; major uncinus short, hroad, thick. 

 Fig. 28. 



Iiucia Gld. 



L. confossa (JilA. (Type.) Minor lateral twisted, peculiar, outer wing broad, re- 

 curved at tip, inner wing small, strengthened by a branch from the shaft (Fig. 29 o) ; 

 rhachidian minute ; major lateral with a quadridentate cusp, shaft with its inner 

 expansion terminating in a cuspidate process above; inner two uncini ridged ; major 

 uncinus feather-shaped, vane on the inner edge (296). Fig. 29. 



Corephium Gray (not Brown), 



C. echinahim Sby. (Type.) Minor lateral with the shaft expanded above, with a 

 cusp confluent with the upper edge of the small inner wing, outer wing small; 

 major lateral with a rounded tridentate black-margined cusp bearing a spot on the 

 middle denticle, shaft keeled in front, keel produced into a thin linguiform process ; 

 major uncinus asymmetrical, somewhat spoon-shaped. Fig. 30. 



Nuttallina Cpr. 



N. scahra Eve. (Type.) Minor lateral normal, bi-alate; major lateral normal, 

 with plain shaft and tridentate cusp ; major uncinus long, slender, with small ex- 

 pansion at the tip. Fig. 31. 



Phacellopleura Cpr. ex Guildiug. 



P. porphyritica Eve. sp. unica. Minor lateral with an inner but no outer wing, 

 otherwise normal ; major lateral normal, with plain shaft and tridentate cusp; inner 

 uncini nodulose ; major uncinus normal, spatulate. Fig. 32. 



B.— lEEEGULAE CHITONS. 



SCHIZOIDEA. 



I have not been able to obtain the radula of any of the few species comprised in 

 the genera Lorica, Atilacochiton, Schizochiton, Enoplochiton, and Onitkochiton. 



PlACIPIIOROIDEA. * 



Placiphora Cpr. ex Gray. 



P. Carmichaelis Gray (= C seUyer King and Fremhhji Brod.). Type. Ehachidian 

 tooth with its edges folded inward. Minor lateral with a large narrow inner wing, 

 small outer wing, and a median keel on the slender shaft; major lateral with a large 

 tridentate cusp, shaft slender, normal ; major uncinus with a small expansion at 

 the tip. Fig. 33. 



Ettphioiphoro. Fmiiblyin (^^^ stirptochUon V\n\). and GiuhViiujia not examined. 



MOI'ALOIDEA. 



Mopalia C\n\ ex Gray. 



M. ciliuta Sby. (Typo, = muHcosa Gld. -f- Hindsii Gray.) Minor lateral normal, 

 bi-aJate; major lateral normal, tridentate with a plain shaft; inner two uncini 

 ridged; major uncinus rather short, normal. Fig. 35, 35 a. 



M. Wossnessenskii Midd. (Kennerliji Cpr.). Similar to the last with a longer major 

 uncinus. Fig. 34. 



Placiphorella Cpr. 



P. velata Cpr. (Type. ) Ehachidian very large ; minor lateral unusually small, 

 both normal ; major lateral tridentate, normal. Fig. 36, 36 a. 



