EUTHVBNIA. 29 



Plectopylis (Sykesia) claihratula, Gude, op. cit. vi, 1899, p. 149. 

 Helix puteolu*, Benson, A. M. N. H. ser. 2, xii, 1853, p. 92 ; Reeve, 

 Conch. Icon, vii, 1854, pi. 190, tig. 1334. 



Original description : " T. late umbilicata, lenticularis, acute 

 carinata, superne liris elevatis (in quovis anfractu 2) et costis 

 distinctis clathrata, paruin nitens, coruea ; spira parum elevata, 

 obtusiuscula ; anfract. 5 subaeq uales, vix convexiusculi, ultimus 

 basi radiato-striatus, circa umbilicum subinflatus ; apertura verti- 

 calis, angusta, angulato-lunaris ; perist. simplex, rectum, acutum. 



" Diam. maj. 5=J, min. 5, alt. 2f mill." (Pfriffer.) 



Hob. Ceylon : Kandy, Balapiti, Badulla (Blanford, Layard, 

 Nevill) ; Ambagamuvva (Collett) ; Balcadua (Simon). 



When first described by Pfeiffer tbe habitat was unknown. 



Benson, in 1853, described what he thought was a new species 

 under the name of Helix puteohis, from Balcadua, Ceylon. Pfeiffer 

 recorded this name as a synonym of his species (Mon. Helic. Viv. 

 iv, 1859, p. 116) and Benson himself subsequently pointed out the 

 identity of the two (A. M. JN T . II. ser. 3, v, 1860, p. 247). 



Fig. 7. Ruthvenia clatliratula. 



The parietal armature consists of a single, slightly oblique, 

 vertical plate, which is slightly twisted and a little notched in the 

 middle, and gives off posteriorly above an obliquely ascending 

 support (see fig. 7 d, which shows the shell with part of the 

 outer wail removed). The palatal armature appears to be some- 

 what variable, and consists of various denticles, arranged 

 principally in two horizontal series, midway between the periphery 

 and the umbilicus. In the specimen figured, which is in 

 Mr. Ponsonby's collection, the first series consists of : posteriorly, 

 a short, strong, flattened vertical tooth, and anteriorly, two short, 

 slight, horizontal denticles, separated by a short space ; the second 

 series consists of : posteriorly, a short, flattened, vertical tooth, a 

 little smaller than the one above it, and, anteriorly, a short, 

 oblique, curved denticle. Below these two series is a longer, but 

 thin, horizontal fold, coincident with the umbilical angulation, 

 while above the vertical tooth of the first series is a minute, 

 horizontal denticle, coincident with the peripheral keel. The 

 specimen measures 5 millimetres in diameter, (^g. 7 a shows 

 both armatures from the posterior side, the anterior palatal 

 denticles being hidden by the posterior teeth ; fig. 7 b gives the 

 anterior view of both armatures, but the posterior tooth of the 

 first series is here hidden by the parietal plate ; fig. 7 c shows 



