HOLOSPIRA. 103 



Cylindrella microstoma PFR., P. Z. S., 1861, p. 27; Malak. 

 Blatter viii, 1861, p. 81; Monogr., vi, p. 390. Holospira 

 microstoma Pfr., FISCH. & CROSSE, Miss. Sclent. Mex., Moll., 

 i, p. 337, pi. 17, f . 9. v. MART., Biologia, p. 278. 



The interior is unknown, but it probably belongs to Ccelo- 

 stemma, differing from H. elizabethce and strebeliana in the 

 angular base, and from the latter in color and the longer ter- 

 minal cone. The figures are from Fischer & Crosse. 



26. H. IMBRICATA (v. Martens). PI. 15, figs. 1, 2. 



Shell imperforate, obovate, swollen above, then passing into 

 a short cone, rather solid, ribbed, gray- whitish ; the apex en- 

 tire, projecting. Whorls 16, flat, the first 2 smooth, following 

 7 rather rapidly increasing, sculptured with strong oblique 

 ribs, the succeeding 4 whorls more slowly decreasing in cali- 

 bre, some being over-lapped by the projection of the preced- 

 ing; penultimate and last whorls arcuately costate, the ante- 

 rior part of the last free, built forward, curved in, the base 

 hardly angular. Aperture vertical, obliquely piriform, peri- 

 stome wanting in the type specimen. Length 16, diam. at 

 10th whorl 8, at penult, whorl 5% mm. ; alt. of aperture 4, 

 width 3 mm. (v . Mart.) 



Mexico (Uhde). 



Cylindrella (Holospira) imbricata MART., Monatsber. 

 Berl. Akad. Wissensch., Nov., 1863, p. 540; Malak. Blatter, 

 xii, 1865, p. 15, pi. 1, f. 2, 3. PFR., Monogr., vi, p. 390. 

 Holospira imbricata Martens, FISCH. & CROSSE, Miss. Scient. 

 Mex., Moll., i, p. 336. v. MART., Biologia, Moll., p. 273, pi. 

 16, f. 25. 



"This very distinct species does not appear to have been 

 found by any subsequent collector. It differs from all others 

 of the genus in the short, club-like form of the shell, the 

 greatest diameter being in the tenth whorl ( at about one-third 

 of the whole length, as seen from above) , the following whorls 

 diminishing remarkably in diameter, and the under edge of 

 some of them projecting a little over the following whorl. 

 Fischer and Crosse 's figure of H . gealei resembles it somewhat 

 in outline, but is not so strikingly swollen above, and wants 

 the vertical costae." (v. Mart.) 



