318 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 85 



marked by concentric lines of growth and almost obsolete corruga- 

 tions; the outer peristome is cut a little anterior to the middle of 

 the inner lip, and posterior to this it is very broadly expanded to at 

 least treble the width of the rest of the outer peristome, the expanded 

 portion extending over the umbilicus as a fold, which it frequently 

 completely covers though at times only partly so ; the outer peristome 

 of the parietal wall is a little narrower than on the rest of the shell 

 and is appressed to and adnate with the preceding turn; the outer 

 peristome shows the color bands as reddish-brown rays; inner per- 

 istome somewdiat expanded and slightly reflected. The breathing 

 pore is at some little distance behind the peristone on the parietal 

 wall and close to the posterior angle of the aperture. The operculum 

 is thin, paucispiral, with submarginal nucleus, the outside covered 

 with a thin deposit of fine calcareous granules. 



The specimen described and figured, U.S.N.M. no. 492992, comes 

 from the north side of Guajaibon without specific designation as to 

 what particular portion of the north part. It has a little more than 

 4 whorls and measures: Length, 12.3 mm; greater diameter, 12.0 mm; 

 lesser diameter, 7.3 mm. 



We have also seen this species from Cacarajicara, a little north of 

 Guajaibon. 



Of this species Gundlach ^ says : "On paradones on the northern 

 slope of Guajaibon. Animal whitish with still whiter dots on the 

 rugosities and especially about the eyes. Head with reddish suffu- 

 sion. Antennae coral-red with white tip. When at rest, suspended 

 by a moderately long mucous thread." 



CHONDROTHYRELLA (CHONDROTHYRELLA) OTTONIS (Pfeiffer) 



Shell moderately large, ovate, ranging from flesh-color to pur- 

 plish brown, unicolor or banded with interrupted spiral bands of 

 brown; peristome white or yellowish. Nuclear whorls 2, well 

 rounded, smooth. Postnuclear whorls inflated, strongly rounded, 

 marked by retractively slanting axial riblets, of which the early 

 ones are usually a little more distantly spaced than the later. The 

 spiral sculpture consists of numerous, very slender threads, like the 

 axial riblets also varying in number and spacing in the different races, 

 Suture well constricted. Periphery well rounded. Base inflated, 

 strongly rounded, and marked by the continuation of the axial 

 riblets and spiral threads, the latter usually a little stronger about 

 the umbilicus than on the rest of the base. Aperture broadly oval; 

 peristome double, the outer flaringly expanded, marked by con- 

 centric laminae, deeply notched on the middle of the inner lip, 

 posterior to which it is reflected over the umbilicus Avhich it com- 



8Malakozool. Blatter, vol. 10, p. 188, 1863. 



