CLASS GASTROPODA 
95 
marked by slender, protractively curved axial riblets, of which 24 occur 
upon the first, 36 upon the second, and about 45 upon the last turn. These 
riblets are almost as wide as the spaces that separate them. In addition to 
the axial ribs the whorls are marked by low spiral cords which equal the 
axial ribs in strength. Of these cords 6 occur upon the first and 7 upon the 
second and the penultimate turn, between the sutures. The spaces inclosed 
between the axial ribs and spiral cords are small, squarish pits. Suture 
moderately constricted. Periphery of the last whorl marked by a sulcus 
equal to those occurring between the spiral cords on the spire. Base 
strongly rounded, somewhat inflated, marked by eight equal and equally 
spaced, somewhat flattened, low spiral -cords, which equal the sulci between 
them in width. In addition, the base is marked by very fine lines of 
growth, which extend over the cords and interspaces. Aperture broadly 
ovate; posterior angle obtuse; outer lip thin, with a very faint varix im¬ 
mediately behind its edge; inner lip moderately strong, strongly curved 
and reflected over and appressed to the base; parietal wall covered with a 
thin callus. Length, 3; diameter, 1.7 mm. (Bartsch.) 
Type in United States National Museum, No. 213690. Type locality, 
U.S. Bureau of Fisheries, Station 3333, off Iliuliuk Harbor, Alaska. 
Range. Iliuliuk Harbor, Unalaska, to Belkoffski, Alaska. 
Alvania compacta Carpenter, 1865 
Plate 82, fig. 7 
Proceedings , Philadelphia Academy of Natural Sciences, 62. Proceedings of the 
United States National Museum, 41:351; PI. 31, fig. 7. 
R. t. parva rufo-fusca, haud turrita, compacta, marginibus spirae excur- 
vatis; anfr. nucleosis iii. globosis, laevibus, apice mamillato; normalibus iii. 
subplanatis latis; lirulis spiralibus obtusis circiter xv., quarum circ. vi. in 
spira monstrantur, interstitiis vix aequantibus; lirulis radiantibus circ. 
xxx., peripheriam tenus evanidis, anfractibus primis superantibus, anfractu 
ultimo saepe obsoletis; basi rotundata, haud (nisi testa juniore) umbilicata; 
apertura suborbiculari, peritremati continuo; operculo tenui, paucispirali, 
rapidissime augente. Long., .06; long, spir., .04; lat., .045 poll. (Car¬ 
penter. ) 
Shell ovate, light chestnut brown. Nuclear whorls two and one-quarter, 
well-rounded, smooth. Post-nuclear whorls well-rounded, slightly shoul¬ 
dered at the summit, marked by poorly developed, slightly protractive, 
axial ribs, of which 24 occur upon the first and second and 30 upon the 
penultimate whorl. In addition to these axial ribs the whorls are marked 
by equal and equally spaced, spiral cords, which are almost equal to the 
axial ribs in strength and of which 6 occur upon the first and 7 upon the 
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