296 PEOCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



Tomcella Carpcutcr. (Typo T. marmorcaYixhv.) 



T. lineaia Wood. Minor lateral with a. long shaft, bi-alate, uormal; major lateral 

 with two small deuticles on the imier side of the cusx> and one large outer denticle, 

 shaft normal; major uncinus spatulate, normal. Fig. 5. 



T. marmorca Fabr. As in the last, but with only one small inner denticle on the 

 cusp of tho major lateral. Fig. 6. 



T. suhmarmorca Midd. Minor lateral shai>cd like a plough.share ; other teeth much 

 as in the last. Fig. 7. 



Schizoplax Dall. 



S. Brandtn Midd. (Typo. ) Minor lateral a broad shaft with a simple cusp, base 

 with a groove or sinus, no wings; major lateral tridentate. Fig. 8. 

 Leptoplax not examined. 



Chaetopleura Shuttleworth. (Type C. Peruviana Lam.) 



C. gemma Cin: Ehachidiau tooth broad and short; minor lateral normal, outer 

 wing inconspicuous; major lateral tridentate, shaft keeled, keel with a small elon- 

 gate cuspidate process. Fig. 9. 



? C. nartwegii Cpr. Minor lateral reduced to a broad cusped shaft with a remnant 

 of an inner wing and a thickened base ; major lateral tridentate, with no keel or pro- 

 cess, shaft normal. Fig. 10. 



Maugerella Cpr. 



M. consjncua Cpr. (Type. ) Minor lateral bi-alate, top of inner wing and shaft bent 

 into a twisted cusp with a small process extending outward from the apex of the 

 shaft ; major lateral tridentate, shaft with a keel and cuspidate process. Fig. 11. 



Spongiochllon not examined. 



ISCIINOCHITONS. 

 Hctcrozona not examined. 

 Stenoradsia Cpr. ' 



S.magdalcnensis'iimds. (Tyjie.) Shaft of minor lateral with a cusp and process, 

 inner wing normal, outer wing inconspicuous; major lateral tridentate, with a keel 

 and cuspidate process on the front of the shaft. Fig. 12. 



Steaoplax Cpr. 



S. limaciformiti Hhy. fType.) Ehachidiau tooth very small ; minor lateral normal, 

 shaft wit-h a minute hook at the apex; major lateral with a simple cusp, shaft bear- 

 ing a keel and cuspidate process; major uncinus very small. Fig. 13. 



Ischnoplax Cpr. 



/. pectinat lis Shy. (Type.) Minor lateral with broad, stout, cusjied shaft, inner 

 wing expanded, outer wing reduced to a rudiment, with a liuguiform process; major 

 lateral with a simple rounded cusp, shaft with a triangular keel but no projecting 

 process. Fig. 2:). 



Ischaochitcn Cpr. ex Gray. (Tyx)0 /. longicymba Quoy.) 



/. cooperi Cpr. Minor lateral with the outer wing reduced to a button near the 

 cusp of the shaff, inner wing small; major lateral with simple cusp, shaft with a 

 keel, bearing a cuspidate process; major uncinus broad, spatulate, thicker near the 

 edges. Fig. 1.5. 



/. iiilcri^tinctus Gld. Minor lateral composed of a shaft with large, twisted, hooked 

 cusi), and possessing only slight rudiments of wings; major lateral tridentate, keeled 

 on the shaft, with a spatulate i^rocess on the keel; uuciui rugose, major uncinus 

 sharply bent, strengthened by narrow ridges on the spatulate cusp. Fig. l(i. 



/. regularh Cin-. Teeth closely resembling those of /. Cooperi, but minor lateral 

 with a small outer wing. Fiji. 14. 



