14 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 69 



The first of these is crossed by the continuation of the axial ribs 

 which cross the second interval but do not cross the second cord. 

 The anterior basal spiral cord is therefore slightly nodulose. Aper- 

 ture elongate-oval; posterior angle obtuse, somewhat effuse ante- 

 riorly; outer lip thin, showing the external sculpture within; inner 

 lip sinuous, reflected over and appressed to the base for three-fourths 

 of its length and provided with a rather conspicuous fold a little 

 anterior to its insertion; parietal Avail covered by a rather thick 

 callus. 



The type (Cat. No. 363090, U.S.N.M.) has lost the nucleus. It 

 has five and one-half postnuclear whorls and measures, length, 1.7 

 mm. ; diameter, 1.1 mm. 



ODOSTOMIA (CHRYSALLroA) COLLEA, new species 



Plate 2, fig. 1 



Shell elongate-conic, bluish-milk-white. Nuclear whorls decol- 

 lated. Postnuclear whorls slightly rounded, appressed at the summit, 

 which falls considerably below^ the peripheral cord and gives to the 

 whorls a decidedly overhanging appearance. The postnuclear 

 whorls are marked by rather strong axial ribs, of which the early 

 ones are retractively curved and the later slightl}^ protractive. Of 

 these ribs, 18 occur upon the first to third and 20 upon the remaining 

 whorls. The intercostal spaces about one and one-half times as wide 

 as the ribs and rather well impressed and crossed by five spiral cords, 

 of which the first is at the summit and is a little stronger than its 

 neighbor anteriorly, which equals the supraperipheral cord in 

 strength, the third and fourth being a little weaker and more closely 

 approximated. The spaces between the cord at the summit and the 

 first below it and between the fourth and fifth are equal and form a 

 series of broadly rectangular pits, while the space belAveen the second 

 and third is a little narrower and that between the third and fourth 

 is even less in width. The junction of the axial ribs and spiral cords 

 form slender elongate tubercles whose long axis is parallel to the 

 spiral sculpture. On almost all the whorls except the first, the first 

 basal cord is apparent in the suture and on the last two whorls this 

 forms a strong almost smooth band, while the axial ribs extend across 

 the channel separating it from the first supraperipheral cord they 

 do not tuberculate the basal cord. Suture moderately impressed, 

 periphery well rounded. Base of the last whorl well rounded, 

 marked by eight moderately strong spiral cords which become pro- 

 gressively weaker from the periphery anteriorly, and also pro- 

 gressively a little closer spaced, the spaces that separate the spiral 

 cord being always a little wider than the cords. These spaces are 

 crossed by threadlike continnations of the axial ribs. Ajierture 



