\ I 



of the last whorl, thin, -imple, pa-.-ini: imperceptibly into f 



twisted pillar which bean a single di.-tinct fold; body whorl with 



only a Lrla/e, pillar hardly r not at all tlii.-kcned ; apertun- app 

 imately lunate. LOD. of shell, 6*0 ; of last whorl. tore, 



4-25. Max. lat. of shell, 4'0; of aperturr, 1 i;-J ,,,ill. , /; 



0/Bahin Ifon.la, Cuba, 310 fms. (Blake,; Off e. coa4 of the 

 led States 1 > ")74 fins. (Verrill). 



Actason m>l<nn/>oides DALL, Bull. M. C. /,., ix. p. !.">, 1**I : I 1 . 

 Rep., Gastr., p. 41, pi. 17, f. 2. A. hebes Vi:i:i:iii. Trans. Conn. 

 Ac-ad, vi, p. 428, pi. 44, f. 15, J 885. 



The A. hcbe*, which Dall believes to he identical, is shown in tiir. 

 12 of pi. 19. 



A. PERFORATUS Ball. PI. 20, fig. 36. 



Shell small, pointed, waxen white, with a narrow opaque yellow- 

 ish hand in advance of the suture, composed of about six whorl-. 

 and with a distinct umbilical perforation ; nucleus eroded, small : 

 spire with about six, or (on the last whorl) eighteen strong and very 

 regularly and distinctly punctate grooves, the punctuations at the 

 rate (near the aperture) of about six to a millimeter, the grooves a 

 little more crowded anteriorly and distant posteriorly, the inter- 

 spaces everywhere wider than the grooves and with no intercalary 

 grooves or stria? whatever; transverse sculpture of faint lin- 

 growth ; aperture rounded in front, pointed behind; outer lip thin, 

 simple, arched, and continuous with the reflected thin pillar lip, 

 upon which a fold can hardly be made out; body with a slight 

 glaze; umbilical perforation straight, with smooth walls, appar- 

 ently very deep, and about 0'25 mm. in diameter. Lon. of shell, 

 7-75; of last whorl, 6'0 ; of aperture, 1 <>. .Max. lat. of shell, 4'62 ; 

 of aperture, 2-0 mill. (Da If). 



Gulf of Mexico, 805 fms. (Blake). One specimen. 



A. perforate DALL, Bull. .M. C. /., Ix, p.96; I'.lak istr. 



p. 42, pi. 18, f. 3. 



It differs from A.exiyun* Dkr. ot'tlioaine re-ion in it- very much 

 shorter spire and globular proportions, in its obsolete columellar 

 fold and the strength and uniformity of its punctate -nl< i. The 

 anterior part of the last whorl being a little larger than any part 

 posterior to it, this shell has a somewhat pyriform appeara 

 (Dall). 



