STROBILOPS, S. G. ENTEROPLAX. 55 



The umbilicus is contained 3I/2 times in the diameter. The 

 internal structure is like the type of hoholensis. The parietal 

 lamellae are slightly more than a half-whorl long, with an 

 irregular, smooth, radial callous band across the parietal wall 

 at their inner ends. Under a high power the rounded edge 

 of each lamella is seen to be closely set with short prickles 

 directed toward the aperture, so that in profile view the ap- 

 pearance is that of a fine but irregular saw (PI. 11, fig. 7). 

 These disappear towards the aperture, and are well developed 

 only near the inner ends of the lamellae. 



19. Strobilops quadrasi (MUdfe.). PL 11, figs. 11, 12, 13, 14. 



Shell rather openly umbilicate, conoid-depressed, thin, cos- 

 tulate above, striatulate beneath, corneous-brown ; spire little 

 elevated, with slightly convex lateral outlines; whorls 6, a 

 little convex, separated by an impressed suture, the last rather 

 acutely carinate at the periphery, obtusely angular around 

 the umbilicus. Aperture diagonal, irregularly heart-shaped; 

 peristome moderately expanded, strongly lipped within, brown, 

 the margins connected by a strong callus which is somewhat 

 deeply sinuate at the insertion of the outer margin and lamel- 

 larly raised. There is a high upper parietal lamella joined 

 to the callus and a lower one not reaching the callus, both 

 entering deeply, and opposite them, a third of a whorl within, 

 three rather strong and long palatal lamellae. Height 1.75, 

 diam. 3.5 mm. (Mlldff.). 



Northern Luzon: village of Siamsiam (J. Quadras) ; Sitio 

 Cobayo, Palanan (Quadras). 



Plectopylis quadrasi Moellendorpf, Nachrichtsblatt D. 

 Malak. Ges XXV, December, 1893, p. 172 ; Abhandl. naturf. 

 Ges. Gorlitz, XXII, 1898, p. 148.— Gude, Science Gossip, lY, 

 August, 1897, p. 71, fig. 54a-e. — Strohilops (Enteroplax) quad- 

 rasi Mlldff. and var. 'brunescens Mlldff., Wenz, Nachrbl. d. m. 

 Ges. 1916, p. 189. 



The parietal lamellee enter half a whorl, and towards the 

 inner end their edges are set with low, rather blunt asperities 

 or granules, less developed than in 8. hoholensis. Across the 

 parietal wall and connecting the inner ends of the parietal 



