50 BULLETIN OF THE 



expect from the greater depth of the ocean representatives resembling 

 those types of animals which were prominent in earlier geological 

 periods, or bear a closer resemblance to younger stages of the higher 

 members of the same types, or to the lower forms which take their 

 place nowadays. And to leave no doubt that I have a distinct per- 

 ception of what I may anticipate, I make the following specific statement. 



It lies in the very nature of these animals that, among vertebrates' 

 neither Mammalia nor Birds can exist in deep waters, and if any Rep- 

 tiles exist there, it could only be such as are related to the extinct 

 types of the Jurassic periods, the Ichthyosauri, Plesiosauri, and Ptero- 

 dactyles ; but even of these there is very little probability that any of 

 their representatives are still alive. Among the fishes, however, I ex- 

 pect to discover some marine representatives of the order of Ganoids 

 of both the principal types known from the secondary zoological period, 

 such as Lepidoids, Sauroids, Pycnodonts, Coclacauthes, Amioids, and 

 Glyptolepis-like species may even be looked for. Among Selachians 

 some new representatives of Cestraciontes or Hybodontes may be 

 forthcoming, connecting the latter more closely to Odontaspis. I also 

 look forward to finding species allied to Corax, or connecting this genus 

 with Notidanus, perhaps also Jurassic-like forms. Among Chimreroids 

 we may expect some new genera more closely related to the extinct 

 types of that family than those now living. Among ordinary fishes 7 

 take it for granted that Beryx genera may be added to our list, ap- 

 proaching perhaps Acanus, or rather Sphenocephaly ; also types allied 

 to Istieus, to Anenchelum, and to Osmeroides, Elops, and Argentina. 

 Dercetis and Blochius may also come up. Species of all classes of the 

 animal kingdom which have been very rarely met with by fishermen 

 and naturalists are likely to be found in the deepest waters, in which 

 neither hooks nor nets are generally lowered. Nothing is known con- 

 cerning the greatest depth at which fishes may live. Upon this point 

 I hope to obtain positive data. 



The Mollusks will, no doubt, afford a rich harvest of novelties, among 

 which some may be of the deepest zoological interest. It stands to 

 reason that a variety of Nautiloid Cephalopods may be discovered 

 when Nautilus proper and Spirula are so rarely found alive, and 

 among new forms there may be those combining characters of Argo- 

 nauts with features of Nautilus ; some may even be coiled up like Tur- 

 rilites. Belemnitic Squids would appear natural. Among Gasteropoda 



