398" F. d'A. Furtacio on Ahurtion of the 



cliael's, one ot" the Azores. These Vitrime were readily 

 distinguished by their more vivid eolour from the species 

 which I had previously found in the island, and which are 

 recorded by M. Morelet as occurring- there. The shell re- 

 sembles in its greenish tint, its dimensions, and its g-enerally 

 globular form that of V. mollis^ which Morelet and Drouet 

 found in Terceira only. 



I lost no time in dissecting one of the specimens, being 

 anxious to compare the organs of generation with those of 

 other species ; but as soon as I had laid open the neck of the 

 animal I was greatly surprised to find that the organs which 

 I looked for were altogether absent. Aly curiosity being ex- 

 cited, I dissected in succession seven specimens ; but in none 

 of these could I find the least trace of reproductive organs. 



The ten examples agreed in colour, outward appearance, 

 and internal structure. Differences of size were observed ; 

 and in some the shells were less inflated than in others. 

 From the size of the shell I infer that the individuals were of 

 about the same age; and as they were all found close to- 

 gether, they probably belonged to one brood. 



It seems to me improbable that ten individuals, the offspring 

 of parents belonging to one and the same species, would offer 

 so remarkable and regular an anomaly ; and I am therefore 

 inclined to think that these Vitrinai are hybrids. Possibly 

 the conditions of life in the Azores may be favourable to hy- 

 bridity among terrestrial Gasteropoda. M. Morelet mentions 

 a Buiiinus intermediate between B. ijrunimis and B. vuhjaris^ 

 which was found in St. Michael's ; and he adds, "on ne trouve 

 d'autre explication il cette siiigularite qu'une alliance adul- 

 t<5rine entre les deux mollusques " ^*, M. Drouet cites the 

 shell of a mollusk, found at Santa Maria, living side by side 

 with Zonites volutella and Z. migueliaus^ which agreed with 

 the former in colour and with the latter in shape f. I have 

 not been able to procure examples of either of these mollusk s 

 for anatomical examination. Probably they were sterile 

 hybrids and have left no descendants. 



The mandible and lingual ribbon of the asexual Vitrina 

 agree perfectly with those of V. brumalis^ the only species 

 Avhich I have been able to study. Before describing the shell, 

 I submit a Table of all the Azorean Vltrince, according to 

 shell-characters : — 



1 



i Riglit margin of peristome reflected Jlniiinia. 



I Right margin of peristome not retiected '2 



* ' Notice sur I'liist. nat. des AQores," pp. 180, \^~ (1800). 

 t ' Elemen't:^ de la faune a9orcenne,' p. 420 (1801). 



