1H82.] MOLLUSCAN FAUNA OF MADAGASCAR. 385 



deposit of callus, before the deposition of which the starting-point 

 of the columella is conspicuously defined by a transverse white line, 

 which starts just above the umbilicus and winds round the penul- 

 timate whorl within the aperture. Operculum generally dirty lilac 

 on the inside, but sometimes white or horny-brown. 



Height 50 millim. ; greatest diam. 49, smallest 38 ; aperture 36 

 long, 23 wide. 



Hab. In a marsh, north of Antananarivo (Johnson) ; Imerina 

 province {Cowan). 



In form this species is not unlike A. largillierti of Philippi, but 

 it is quite distinct in several respects. The spiral striation is finer, 

 the umbilicus broader ; the aperture is not angular or effuse at the 

 base, nor has the last whorl the rounded keel or ridge at the base 

 around the umbilical fissure. 



A. cecillei, Phil., appears to be more ovate, with less tabulated 

 whorls, has a higher spire, and is differently coloured. 



It is only in adult specimens that the commencement of the 

 aperture near the lip is yellow. The columella is also of that colour 

 in full-grown shells, but bluish white in young ones. This species 

 appears to arrive at maturity after two years' growth, as all the large 

 specimens exhibit a dark longitudinal stripe or former lip just before 

 the completion of the fifth whorl. In the young state this is very 

 thin, and the colour is horny-brown, and not greenish olive like the 

 last large whorl of the adult. 



LiMN.«A HOVARUM, Tristtam. 



Limnosa hovarum, Tristram, Proc. Zool. Soc. 1863, p. 61. 



Hab. Ankafana, Betsileo {Cowan). 



This speciesgrows to alarger size than that of the specimen described 

 by Tristram ; lor one from the above locality is as much as ten lines 

 long. In the larger shells the lines of growth become more pro- 

 minent, forming arcuate and tortuous elevated ridges. The columella 

 also is reflexed, appressed to the whorl, yet leaves a shght chink or 

 rimation in the umbilical region. All the specimens examined 

 exhibit traces of transverse or spiral striae, generally interrupted and 

 of a subpunctate character. 



LiMN^A ELECTA, sp. uov. (Plate XXII. figs. 12, 13.) 



Shell small, ovate, transparent, corneous, narrowly rimate. Whorls 

 3-3^, convex, rapidly increasing. Spire small, obtuse and reddish 

 at the apex. Last whorl elongate, sculptured with fine lines of growth 

 crossed by a few spiral striee. Aperture vertical, ovate, acuminate 

 above, occupying about two thirds of the entire length of the shell. 

 Columella rather high up, reflexed over the umbilical fissure, the 

 refiexed portion being striated rather coarsely lengthwise. 



Length 6| milhm., diam. 4 ; aperture 4| long, 2| wide. 



Hab. x\bout 20 miles from Antananarivo {Johnson). 



This little species has much of the general aspect of the genus 

 Succinea, and is peculiar on that account and the red tip of the 

 sjtire. 



