78 



HOLOSPIRA. 



MART., Malak. Blatt., xii, 1865, p. 15. Not C. goniostoma 

 Sowerby, Conch. Icon., xx, pi. 8, f . 72. Holospira goniostoma 

 FISCH. & CROSSE, Miss. Sclent. Mex., Moll., i, p. 328, pi. 17, f. 

 4. STREBEL, Beitrag, iv, p. 84, pi. 14, f. 6 A, B. c (axis). 

 CROSSE, Journ. de Conchyl., xl, 1892, p. 264. v. MART., Bio- 

 logia, Moll., p. 280. 



Strebel's figures of the shell (fig. 37), the internal column 

 (fig. 38) and the lamellae (fig. 36) are reproduced on my plate. 

 He writes: The shell is rather lengthened, cylindric, rather 

 translucent, brownish-horn colored, lighter and becoming 

 somewhat whitish below, and set with fine, sharp, pretty 

 closely placed and somewhat oblique ribs, distinctly white and 

 continuing to the suture. On the upper half of the shell they 

 are rather straight, on the lower half somewhat curved, cor- 

 responding to the flatness of the upper, and the greater con- 

 vexity of the lower whorls. The embryonic whorls are smooth 

 and brownish horn-colored, placed somewhat obliquely and 

 button-like; the following whorls increase very slowly in 

 height, are separated by a deep suture. The last whorl is 

 compressed, feebly angular at the base, the free portion pretty 

 long, as it has been already described. The umbilicus is 

 closed. The internal column (fig. 38) is rather conspicuously 

 widened above the middle, narrowing again towards the apex ; 

 below it is rather narrow as a whole, and besides the dilation, 

 in each whorl, shows a dilation running spirally, which to- 

 wards the lower whorls is more and more thickened into a 

 lamella, which finally projects rather broadly into the whorl, 

 then in the last whorl rapidly diminishes again, and does not 

 reach to the aperture, where there is visible only a somewhat 

 oblique, indistinct, columellar fold. The three characteristic 

 lamellae in the interior of the last whorl have the following 

 disposition : The largest, cord-like, depends from the partition 

 between the whorls, begins in the third whorl from the mouth, 

 and runs to almost the beginning of the last whorl. It in- 

 creases in height gradually, and diminishes more rapidly. 

 The second (basal) lamella runs between the penultimate and 

 last whorls, but is only a half whorl in length. It is more 

 calloused, and only towards the end on the outer side projects 



