450 PROCEEDINGS OF THE ACADEMY OP [1896. 



tooth tricuspid ; 14 perfect laterals with two rather widely separated 

 cusps, the outer shorter ; the lower edge of the base of attachment 

 thinned out as usual in the genus ; marginals low, wide, bicuspid, 

 the cusps subdivided into minor denticles giving a serrate look to the 

 outer marginals. 



This species is of a reddish-yellow color, with the apex of a pro- 

 nounced rosy tint, the surface somewhat rough as in S. Bettii, from 

 which it differs by its more produced spire and the manner in which 

 the outer lip is bent over so as to reach the body whorl vertically 

 instead of obliquely. Only young, and very few even of the young, 

 are quite as slender as the one figured by Reibisch. The outer lip 

 in fully adult specimens is more expanded than in S. Bettii, both 

 have a gyrate and pervious axis, but the S. Bettii has it more open 

 than the other species. 



Succinea corbis Dall. Plate XV, fig. 6. 



Succhiea corbis Dall, Nautilus, VII, p. 55, Sept., 1893. 



South Albemarle Island, on dry bones of turtles, Dr. Baur. 



Shell small, of two and a half whorls, to which a black mould ad- 

 heres with tenacity. The first whorl and a half are salmon-pink in 

 the adult, but in the young of that size are pale amber colored. 

 The shell resembles S. produeta in form, but is smaller and has a 

 more contracted aperture, it is instantly recognized when examined 

 with a good lens, by its surface, which is minutely shagreened all 

 over with an excessively fine network of closely reticulated incised 

 lines. Alt. of shell 7, max. diam. 4*5, extreme length of aperture 4 

 mm. 



The remarkable sculpture is not visible to the naked eye except 

 as a sort of hoary bloom on the surface ; under a compound micro- 

 scope it looks like closely woven basket work. I have examined a 

 great many Succineas without finding any other species possessing 

 this character, but, from the description, S.solidula Pfr. from Christ- 

 mas Island, in the Indian Ocean, must have somewhat such a sur- 

 face. Mr. Edgar A. Smith (P. Z. S., 1887, p. 518) states that S. 

 solidula has " the texture of very fine linen, or minute criss-cross 

 lines," which fairly well describes the surface of S. corbis. S. soli- 

 dula exhibits the further peculiarity of having a slight but evident 

 internal thickening of the peristome, but as the specimens of S. cor- 

 bis are all evidently immature or not fully grown, they would show 

 nothing of such a character even if the fully adult possesses it. A 

 close examination of the black earthy substance with Avhich the 



