234 BECHER : MOLLUSCA OF THE MALTESE ISLANDS. 



formed specimen. To the casual observer it appears some- 

 times deeply umbilicated and sometimes not. The reason 

 of this is that the inner extremity of the lip is reflected 

 back, covering more or less the umbilicus, which covering 

 is very frequently broken. Benoit mentions several locali- 

 ties in Sicily where it is common. 

 H. melitensis Fer. — Not uncommon. A light cream-coloured 

 shell with faint dark markings in the direction of the line 

 of growth ; sometimes almost absent. Not found in Sicily. 



H. verm icu lata Linn. — Appears to be as common in Sicily 

 as it is in Malta. It varies considerably in colour ; a light- 

 brown variety with few, if any, markings is not uncommon. 



H. pisana Miill. — Very common everywhere. There is con- 

 siderable colour variety. A peculiarity about this species 

 as well as some others, notably H. cespitum Miill., is that 

 at the approach of summer, instead of retiring to shady 

 places, they are to be found on exposed twigs, etc., where 

 they are without any shelter from the fierce heat of the 

 sun. As common as the last in Sicily. 



H. cespitum Miill. =J^ variabilis Drap. — Very common, 

 especially along the shore near Marsa Scirocco. Very 

 common in Sicily. 



H. conspurcata Drap. — Common, especially on Manoel 

 Island, where they are to be found many together under 

 stones, and in the crevices of the fortifications. It is very 

 common in Sicily. 



H. lenticula Fer. — Common in similar localities to the above. 

 Those I have obtained at Malta have all been considerably 

 smaller than my Gibraltar specimens. • 



H. Erdelii Roth. — This is not a common species. It is 

 named H. flavida Ziegl. in the collection at the Valletta 

 University ; the shell is somewhat the shape of Zonites, 

 horn colour, semi-transparent, strongly striated along the 

 line of growth. 



J.C, iv., Oct., 1884. 



