4G4 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



cellular, and that in Macrodon there was no cellular portion. 

 M. Jobert's investigations purport to have been based on 

 three species E. tcmiatus and E. brasiliensis, in which the 

 air-bladder was found to have a cellular area ; and E. trahi- 

 m, in which there was none. The E. tcmiatus is doubtless 

 the E. imitce?tiatus,b\\t the E. brasiliensis of Spix is apparent- 

 ly the same as E. trahira (Maerochn), which has no cellular 

 air-bladder, and consequently M. Jobert must have made an 

 erroneous identification. Nothing could better attest the 

 close relationship of these forms, so different physiologically, 

 than such a mistake. 



Egg-laying Sharks and Rays. 



A number of communications have been published in pop- 

 ular periodicals, and otherwise, during the past year, respect- 

 ing viviparous and egg-laying sharks and rays, which show 

 the advisability of a brief statement of facts. Contrary to 

 the popular impression, viviparity is the rule, and oviparity 

 the exception, among the Selachians. Of the ten families of 

 sharks represented along the eastern coast of the United 

 States, nine are viviparous, and only one oviparous ; that one 

 being the Ginglymostomidce , of which a single species oc- 

 curs, mostly confined to Florida. Of the six families of 

 rays, five are characterized by viviparity ; and the only egg- 

 laying forms are the species of skates, or ordinary rays. 

 But while the family of liaiidce is the only one of the order 

 of jRaice in which oviparity is manifested, there are several 

 of the order of Squall, the chief of which is that of ScyUiidce. 

 M. Vaillant has lately (in the Comptes Mendus of the French 

 Academy of Sciences, vol. lxxxvi., pp. 1279-1281) given a 

 lengthy description of the eggs of Stegostoma (one of the 

 ScyUiidce)^ which had been previously unknown. 



Deep -Sea Fishes. 



The past has been a fruitful year for the knowledge of the 

 fish inhabitants of the deep seas. Above all are the glean- 

 ings of the Challenger, which have been submitted to Dr. 

 Giinther ; but besides these are the results of waifs from the 

 deep-sea fishing-grounds of the Gloucester fishermen, as well 

 as estrays described by Dr. Liitken, from Greenland, and by 

 Mr. T. E. Clarke, from New Zealand. 



