278 PROCEEDINGS OF THE NATIONAL MUSEUM Vol.89 



The type, U.S.N.M. No. 493487, was collected by Gundlach at 

 Mata, Oriente Province. It has 6.4 whorls remaming and measures: 

 Length, 9.8 mm.; greater diameter, 5.2 mm.; lesser diameter, 4.5 mm. 



This species most nearly resembles Tudora (Wrightudora) garridoiana, 

 from which it can be readily distinguished by not having the axial 

 riblets arranged in alternate series of strong and feeble assemblages. 



TUDORA (WRIGHTUDORA) SEMICORONATA ([Gundlach] Pfeiffer) 



Plate 28, Figure 4 



1861. Cyclostoma semicoronatum [Gundlach] Pfeiffer, Malakozool. Blatter, 



vol. 7, pp. 28-29. 

 1865. Ctenopoma semicoronatum Pfeiffer, Monographia pneumonopomorum 



viventium, suppl. 2, p. 117. 

 1920. Ramsdenia semicoronata Henderson and Bartsch, Proc. U. S. Nat. Mus., 



vol. 58, p. 79. 



Shell small, thin, elongate-conic, straw colored. Nuclear whorls 2, 

 inflated, well rounded, microscopically granulose, forming a rather 

 elevated tip. Postnuclear whorls inflated, strongly rounded, almost 

 angulated in the middle, marked by retractively slanting, lamellar 

 axial riblets, which are expanded into rather strong auricles at the 

 summit and at the periphery; in adjacent whorls these two elements 

 occasionally fuse. The axial riblets are hollow, and series of 2 to 4 

 strong riblets are separated by series of a similar number of weaker 

 threads; of these riblets, 68 occur on the first, 112 on the second, and 

 118 on the last whorl. The spiral sculpture consists of moderately 

 strong threads, which render the riblets wavy and scaUoped at their 

 junctions. Of these riblets, 4 occur on the first and 5 on the remaining 

 turns between summit and suture. Suture strongly constricted. Base 

 short, weU rounded, openly moderately broadly umbilicated, marked 

 by the continuation of the axial ribs and 3 spiral cords, of which the 

 one marking the angle of the umbilicus is stronger than the rest. 

 The umbilical wall is marked by the continuation of the axial riblets 

 and by 6 slender spiral threads. Last whorl solute for about one-fifth 

 of a turn. Aperture subcircular; peristome double, the outer broadly 

 expanded, strongly scaUoped at the edge, narrower on the parietal 

 wall, produced into a moderately strong auricle at the posterior angle; 

 inner peristome slightly exserted. Operculum as described for the 

 species. 



This species comes from Mata, Oriente Province. Gundlach says 

 of it (Malakozool. Blatter, vol. 7, p. 29, 1861): "Animal brownish 

 white. Dark dots form small spots and patches upon the snout and 

 head. The region about the eye is rosy white ; the interior of the head 

 and antennae rose colored or rather bright coral red with fainter 

 grayish apex. A dark coloration is present between the neck and 

 foot." 



