fSTANDEN : CALCAREOUS EGGS OF TERRESTRIAL MOLLUSCA. 163 



(C. B. Ads.), from Santa Clara, six calcareous, white, globular eggs, 

 17 to I '8 mm. in diameter. The eggs of Cryptelasmus canteroiana 

 Gund., from Trinidad, are calcareous, very much flattened and i"25 

 mm. in greatest diameter. Those of Spiraxis simplex Guppy, from 

 Trinidad, are white, calcareous, and closely resemble those of Subu- 

 ii?ia. 



The eggs oi Eucalodui?n are elliptical, the shell hard, white, rough 

 to the touch, and showing crystalline facets under a lens. They are 

 comparatively large, that of ^. decoUattan (Nyst) measuring ii'2 x 7-2 

 mm. E. mexicanmn Pfr. is said by Crosse and Fischer to have a 

 similar egg, but that of E. ivalpoleaimm Crosse and Fischer (belong- 

 ing to the sub-genus OUgostylus) is smaller and narrower, 7x4 mm. 

 Coelocentriim gigas Mts. has a short oval egg, 3"5 x 2"5mm. It is 

 roughened by numerous white polished crystalline facets, which give 

 it the appearance of being frosted over, and is a strikingly beautiful 

 microscopic object. A. A. Hinkley writes to G. C. Spence that he 

 found this species on the mountain-sides, west of Livingston, Guate- 

 mala, in thick timber. The eggs are deposited under dead leaves, in 

 small depressions made by the snail in the soft mould. The place 

 selected is always a little open, so that the sun may shine thereon for 

 a short time during the day. Very little seems to be known of the 

 reproduction in other Urocoptid genera. G. C. Spence has recorded 

 the finding of white calcareous eggs inside the shells of several species, 

 which are presumably ovoviviparous. In Anoma solida (C. B. Ads.) 

 the egg is long-oval, i x f5 mm. ; in Urocoptis lavalleana d'Orb., 

 round, diameter i mm. ; in U. intusnialleata Gund., round, diameter 

 ■9 mm. ; and in Microceramus tnexicanusVix., round, diameter 75 mm. 

 (y\die/ourn. of Conch., vol. 15, p. 12). 



That such fragile objects as the calcareous eggs of snails should be 

 found fossil seems surprising, yet they occurred m considerable num- 

 bers in Pleistocene deposits in a cave at Dog Holes, on Warton Crag, 

 near Lancaster, which was excavated by J. Wilfrid Jackson in 190 7-9. 

 They were associated with an immense number of land mollusca, 

 mainly minute species. They were also found by W. J. Lewis Abbott 

 in the Ightham Fissures, Kent, in a deposit of similar age and char- 

 acter. The eggs apparently belong to several species of ZT^Z/jc and 

 Hyalinia. As the eggs of snails are known to be attacked by minute 

 Diptera, which pierce and lay their eggs in them, it is not unlikely 

 that the small, regularly drilled hole present in many of the fossil eggs 

 may have originated in similar attacks by this class of insects. In 

 writing of a series of the fossil Chilonopsis nonpareil (Perry), collected 

 by Colonel Turton at Sugarloaf Mountain, St. Helena, E. A. Smith 

 remarks that some fossil snails' eggs obtained with the shells evidently 

 from their size belong to them ; they are roundly-ovate, and measure 



