8 PROCEEDINGS OF THE ACADEMY OF [Jan., 



Nucula slackiana (Gabb). 



Leda slackiana Gabb., Jour. Acad. Nat. Sci., IV, 2 ser., 397, pi. 68, f. 37. 

 Also specimen figured b}^ Whitfield (Mon. U. S. Geol. Sur., IX, 103, 

 pi. XI, f. 3). 



LEDIDJE. 

 Leda pinnaforme Gabb, Jour. Acad. Nat. Sci., IV, 2 ser., 303, pi. 48, f. 23. 



Also specimen figured by Whitfield {Mo7i., IX). 



Leda protexta Gabb, Jour. Acad. Nat. Sci., IV, 2 ser., 303, pi. 48, f. 23 (not 24). 



Perrisonota protexta Conr., Amer. Jour. Conch., V, 98, pi. 9, f. 24. 

 Represented by three specimens; the smaller one, and not the speci- 

 men figured by Whitfield (pi. XI, figs. 14, 15), is probably the type, or 

 one figured by Conrad. 

 Yoldia longifrons Conrad. 



Leda longifrons Conr., Jour. Acad. Nat. Sci., IV, 2 ser., 281, pi. 46, f. 18. 

 Nucularia papyria Conrad, Amer. Jour. Concb., V, 44, pi. 1, f. 7, and p. 98, pi. 9, 1". 25. 



AROIDuE. 



CucuUaea vulgaris Morton, Amer. Jour. Sci., XVII, 1 ser., 285, and XVIII, pi. 3, f. 21, 1830 ; 

 Syn. Org. Rem., 64, pi. 3, f. 8 ; pi. 13, f. 6, 1S34. 



Represented by 16 specimens accompanied by Morton's original 

 label (No. 393), but the specimen is not numbered and the figure is too 

 poor to positively identify. 



Cuoullaea antrosa Morton, Syn. Org. Rem., 65, pi. 13, f. 6, 1834. 



A specimen marked "type" in Gabb's handwriting. 



Cucullaea tippana Courad, Jour. Acad. Nat. Sci., Ill, 2 ser., 328, pi. 35, f. 1, 1858. 

 CucuUsea capax Conrad, Jour. Acad. Nat. Sci., Ill, 2 ser., 328, pi. 35, f. 2, 1858. 



Both C. tippona and C. capax will probably prove to be synonyms 

 of C. vulgaris Morton. 

 Cucullaea maconensis Conrad, Jour. Acad. Nat. Sci., IV, 2 ser., 281, pi. 47, f. 20, 1860. 



Type of the genus Trigonarca Conr. (Am. Jour. Conch., Ill, 9, 1867). 



Cucullaea neglecta Gabb, Proc. Acad. Nat. Sci., 1861, p. 326. 



The species is based on a number of specimens; the actual type can- 

 not be defined. Whitfield considers it the same as C. antrosa Morton. 

 If so it is the j^oung. 



Cucullaea transversa Gabb, Proc. Acad. Nat. Sci., 1861, p. 326. 



The specimen figured by Whitfield as Trigonarca transversa (pi. XII, 

 figs. 14, 15) is not the type. I found the true type in a drawer contain- 

 ing material marked "Gabb collection." This is not the C. transversa 

 Rogers, 1839, and being preoccupied, I propose the name of C. gahbi 

 for this species. 



