1891.] MR. E. A. SMITH ON SHELLS FROM ADEN. 399 



we find that they have as near representatires in the Indo-Pacific. 

 In the case of the fourth species, Tellina isseli, I am not aware that 

 it has been found anywhere except in the Gulf of Suez, a fact which 

 to some extent confirms its distinctness from the Mediterranean 

 T. balaustina, considering that all the other species common to the 

 two seas have an enormous distribution. 



In the foregoing observations no reference has been made to the 

 light which Palaeontology may throw upon the subject of distribution 

 of the species in question. It is true that most of them are found 

 fossil in the Miocene, Pliocene, and other Tertiary rocks of Italy, 

 Sicily, &c., a fact which would seem to indicate a long establishment 

 in the northern hemisphere. On the other hand, a number of recent 

 Mediterranean and Atlantic forms have already been recorded from 

 the Tertiary deposits of Australia ' ; and we may therefore conjecture 

 that when the Palaeontology of Australia and other eastern countries 

 has been more fully worked out, many more so-called European 

 species will be discovered. Such being the case, I fail to perceive 

 that the evidence aiforded by Palaeontology lends more support to 

 any one of the theories of distribution set forth than to another. 

 Probably all are wrong. 



List of the Yerhury and Baynham Collections of Shells 

 from Aden. 



I. GASTROPODA. 



1. CONUS SUMATRENSIS, HwaSS. 



Hah. Red Sea {Reeve ^- others). Gulf of Akaba {Brit. Mus.) ; 

 Aden {Caramagna). 



2. CoNus CAPiTANEus, Linn. 



Hab. Ceylon, Philippines, Australia, New Caledonia, Polynesia, 

 Mauritius. Andaman Is. {Brit. Mus.). 



3. CoNus RATTUS, Hwass. 



Hab. Red Sea, Ceylon, New Caledonia, Tahiti, &c. Islands of 

 Rodriguez and Annaa {Brit. Mus.). 



4. CoNUS TESSELLATUS, Bom. 



Hab. Red Sea, Persian Gulf, Ceylon, Mozambique, Mauritius, 

 Philippines, New Caledonia, Polynesia. Island of Rodriguez, 

 Torres Straits, Fiji Islands {Brit. Mus.); Aden {Caramagna). 



5. CoNus auERCiNUS, Hwass. 



Hab. Red Sea, E. Africa, Mauritius, Ceylon, Philippines, Viti 

 Islands, Sandwich Islands, New Caledonia, Friendly Islands. 



Some adult specimens 80 millimetres long, obtained by Major 

 Yerbury, are entirely without the spiral thread-like lines which 

 occur in young shells. They are covered with a very thick fibrous 

 or spongy epidermis. 



1 R. Etheridge, jun., Oat. Australian Fossils, 1878. 



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