1896.] NATURAL SCIENCES OF PHILADELPHIA. • 473 



canal. Aperture contracted above and below ; columella with 2 

 fairly well defined plaits. 

 Locality, Jackson, Miss. 



Mazzalina inaurata var. Con. PI. XVIII, fig. 14. 



This is very near to, if not identical with, Conrad's Mazzalina 

 pyrula from the lower Claiborne beds of Alabama. We have already 

 shown in our report on the Tertiary of Arkansas how many forms 

 this species assumes. 



Locality, Jackson, Miss. 



Murex marksi Harris. PI. XVIII, fig. 15. 



This, as well as typical marksi from the Eocene of Arkansas, ap- 

 proaches very closely to 3f. engonatus, and, when specimens enough 

 shall have been collected, the two will doubtless be proven identical. 

 This has seven costse instead of six. 



Locality, Jackson, Miss. 

 Monoceras jacksonium n. sp. PI. XVIII, fig. 16. 



Specific characterization. — Size and general form as indicated by 

 the figure ; whorls about 6 ; the upper 2 or 8 smooth ; 4 and 5 

 strongly costate medially and below ; spiral strise about 8 in num- 

 ber; body whorl nearly smooth, with a strongly marked humeral 

 zone on which are found about 6 spiral lines ; medially smooth ; 

 basaliy more or less strongly spirally striate, with a depressed band 

 across which the lines of growth arch forward, hence giving rise to 

 a tooth like projection on the subcentral portion of the labrum ; 

 columella smooth, labrum lirate within, though the lirse do not ex- 

 tend far in the interior; anterior canal peculiarly truncated below. 



Locality, Jackson, Miss. 

 Levifusus branneri Harris. PI. XIX, fig. 1. 



This species was described from a young specimen found in south- 

 ern Arkansas. Fragments of larger specimens were found by the 

 writer at White Bluff on Arkansas River, and still others in the 

 Jackson beds of Mississippi. This is by far the most perfect large 

 specimen yet known. Its close relationship to Fulgur must be evi- 

 dent to all. 



Locality, Jackson, Miss. 



Siphonalia jacksonia n. sp. PI. XIX, fig. 2. 



Specific characterization. — Size and general form as indicated by 

 the figure; whorls 7 or 8 ; marked by 10 rounded, longitudinal 

 costse, each in width a little over one-half that of the intermediate 



