-M.Mivi.wi) (ii:oi,o(ii('.\r. survky lio 



Length, ]8 iiiiii.; widlli, 15 by 8 iiiiu. (ci-iislicd). 



Ornirrciice. — Nanjk.mov P'okm \'ii<»\. West ul' I'ort Toljaceo, J iiiilu 

 ))('lii\v ('liapel roiiit. Head of NaiijciiiDy Cruek. 

 Cullciiiun. — Marylaiul CJeolnj^ieal Survey. 



Family STROMBIDAE. 



Genus CALYI'TRAPHORUS Coniad. 



Calyptrapiiokus jacksoni Clark, 



Plate XXV, Figs. 1, la, 2. 



C(ihji)l rojiliornti jifksoiil Chirk, 1SU5, Joluis Hopkins Univ. Circ, vol. xv, p. 4. 

 Ca! i/ptrop/ior us Jnrksoiii. Cliirk, ISIXJ, Hull. 141, U. S. Geol. Survey, p. 68, pi. xii, 

 lis,^s. 2a, '2b. 



Description. — "Shell large, solid, many wliorled; spire prolonged, acu- 

 minate; surface of adult covered with thick, calcareous deposit, entirely 

 enveloping the whorls; inner lip thickened with extensive callosity." 

 Clark, 1896. 



This very remarkahle form is (jiiite distinct from any other species, hut 

 some of the Gulf types approach it in size and amount of callosity. 

 Some of the largest specimens of C. tniwcliferus Conrad show certain 

 points of similarity, hut the Maryland species cannot he confounded 

 with it. In the absence of young shells, the character of the surface 

 decoration is unknown. A large number of specimens have been found 

 in the South Eiver area. 



Length (restored), 102 mm.; width, -ii mm. 



Occurrence. — i^QuiA Foemation. Sonth Eiver, Upper Marlboro. 



Collections.- — Maryland Geological Survey, Johns Hopkins University, 

 Museum of Comparative Zoology. 



Calyptraphorus teixodiferus Conrad. 

 Plate XX Y. Fig. 3. 



Calyptraphorus trinodiferus Conrad, 18.57, Proc. Acad. Nat. Sci. Phila., vol. is, 



p. 166. 

 Calyptraphorus trinodiferus Conrad, I860, Joiir. Acad. Nat. Sci. Phila., 2nd ser.. 



vol. iv, pi. xlvii, fig. 29. 



Description. — '' Snbfusiform, with three distinct nodes on the upper 



part of the body volution; spire subtriangular, having curved longitu- 

 10 



