384 MRS. J. LONGSTAFF ON THE HABITS 



and oviparous, and also that var. obesa had one brood entirely 

 ovo viviparous. A dead specimen of the latter variety, found 

 associated with the living ones, contained a number of dead 

 young shells, with which no eggs were noticed. 



Dr. Pilsbry* states that Cochlitoma is ovoviviparous, and gives 

 an instance of Semper having found in the uterus of a specimen 

 of C. zebra sixty undeveloped eggs with calcareous shells, the 

 largest measuring 6 mm. in length and the smallest 3 mm., 

 together with twenty-five embryos which had crawled out of the 

 egg-shell. Further f, he remarks that Mr. Clapp found young 

 shells of about 8 mm. in diameter inside a specimen of C. craw- 

 fordi (Morelet), with which there were no traces of calcareous 

 egg-shell. 



The dimensions of the eggs of the different broods vary : 

 var. fulgurata has the largest eggs — these are preserved in such a 

 manner as to show the structure best. The eggs are calcareous, 

 yellowish in colour, and short-oval or rounded in form. The 

 biggest measure 9 mm. in length by 7 # 5 mm. in width ; the 

 smallest 3*75 mm. in length by 3 - 25 mm. in width. Inside the 

 outer calcareous shell there is an amber-coloured layer which 

 does not cover the whole of the interior, and which appears to 

 give rise to the embryonic molluscan test. Fully a dozen of the 

 broken eggs of var. fulgurata contain the embryo and exhibit a 

 very thin grey layer, more or less calcareous, covering the aper- 

 ture and the greater part, if not the whole, of the shell. The 

 young shell consists of little more than three whorls, of which 

 the earliest is smooth, pale horn-colour, with the apex slightly 

 sunk ; the succeeding whorls have spiral lines crossing the lines 

 of growth and rendering the surface granulated ; the brown- 

 coloured markings begin on the last third of the body-whorl, 

 before it leaves the egg, and they form an interrupted spiral 

 band with a few longitudinal brown lines near the aperture. The 

 soft parts of the animal have entirely disappeared from all the 

 eggs. A young shell, released from a broken egg, had a length of 

 7*5 mm. and width of 8 mm. 



The later brood of var. fulgurata (offspring of the original 

 specimen) contained fewer eggs but more living young molluscs. 

 I broke one of the twelve eggs, and found it was not so far 

 advanced as some of those of the first brood, as there was only 

 the amber- like layer inside the calcareous shell. The largest 

 measures 8-25 mm. in length by 6*5 mm. in width ; the smallest 

 6 - 5 mm. in length by 5*5 mm. in width. 



One of the biggest eggs of the larger example of var. obesa 

 measured 8 mm. in length and 6 mm. in width ; one of the 

 smallest, 3 mm. in length and 2'5 mm. in width. The biggest 

 egg of the smaller parent is less, measuring 5 - 5 mm. in length by 

 4 mm. in width. 



The latest brood, which is probably mixed, contains eggs 



* Man. Conch, vol. xvii. ser. 2, p. 77. 

 t Ibid, v. 93. 



