48 BULLETIN 192, UNITED STATES NATIONAL MUSEUM 



This is a most variable species and for this reason exceedingly 

 puzzling. It appears to extend along the coast line from the Haitian 

 American Sugar Co. establishment north of Port-au-Prince to west of 

 Miragoane. We also have it from Mount Rochelle. There are also some 

 dead specimens from Aquin and St. Louise from the south coast. It is 

 possible that these may be crab-carried. 



I have given a photograph of a series of specimens showing the range 

 in size. The smallest specimen, figured as plate 7, figure 6, has 3.8 whorls 

 remaining and measures: Length, 7.2 mm.; greater diameter, 4.7 mm. ; 

 lesser diameter, 3.3 mm. The largest specimen, figured as plate 7, figure 

 9, has 4.9 whorls remaining, and measures: Length, 14.8 mm.; greater 

 diameter, 7.3 mm.; lesser diameter, 6 mm. The illustration will show 

 the range of intermediates. 



CHONDROPOMA (ARTICUMPOMA) rOWEANUM (Pfeiffer) 



Plate 8, Figure 3 



1854. Cyclostoma (Chondropoma) Loweanum Pfeiffer, Proc. Zool. Soc. London, 



1852, pp. 142-143. 

 1854. Cyclostoma Loweanum Pfeiffer, Martini-Chemnitz Conchylien Cabinet, 



vol. 1, sect. 19, pp. 367-368, pi. 47, figs. 15, 16. 



Shell elongate-ovate, rather thin, whitish, marbled with brown and ir- 

 regularly streaked. The postnuclear whorls are somewhat inflated, 

 strongly rounded, and marked by low lamellar axial ribs, which become 

 intensified near the summit where they form false tufts; they do not be- 

 come fused here as in Chondropomorus. The central members of these 

 tufts are higher than the rest, and the group slopes fore and aft. These 

 ribs are narrower than the spaces that separate them and are rendered 

 vertebrated by the spiral threads, which are also narrower than the 

 spaces that separate them. The suture is rendered serrulate by the tufts. 

 Periphery inflated, well rounded. Base narrowly umbilicated, somewhat 

 inflated, well rounded, and marked by the continuations of the axial 

 ribs and spiral threads, which becoine increasingly stronger from the 

 periphery toward and in the umbilicus. Last whorl solute for a short 

 distance. Aperture ovate; peristome simple, somewhat thickened at the 

 edge. Operculum said by Pfeiffer to be like that of Chondropoma pictum. 



I have not seen specimens of this species but have based my descrip- 

 tion partly upon Pfeififer's diagnosis and in part upon an enlarged photo- 

 graph of the type here reproduced. Pfeiffer states that the specimen was 

 gathered by Salle in "Santo Domingo." 



The type is in the British Museum and has almost 7 whorls and 

 measures: Length, 17.0 mm.; greater diameter, 9.0 mm. 



The simple lip and large size will distinguish this species from all the 

 other known Haitian Articulipomas. 



