STEENSTRUP ON THE BASKING SHARK. 123 



VIII. — On the Straining Appendages or Branchial 

 Fringes of the Basking Shark (Selachus maximv^, 

 Gunn.). By Prof. Dr. Japetus Steenstrup. 



[Abstract of the Memoir in the Overs, over d. K. D. Vidensk. 

 Selsk. Forhandl., 1873.] 



Dr. Steenstrup offers an explanation of certain appendages 

 many feet in length, consisting of long, hornlike rays resembling 

 beard or comb-like fringes, which have long been the object of 

 research. 



Professor Hannover showed, in his work on the dermal spines 

 of Rays and Sharks, that these rays have the same structure as the 

 spines, being formed of bony matter and identical with true teeth. 

 Not admitting with Hannover that these rays are situated on 

 the outer skin, like the spines of certain Rays, Steenstrup has 

 always supposed, from their form and disposition, that tbey filled 

 an office similar to that of the beard-like gums of the Whale. 



Such straining appendages, composed of a series of distinct 

 teeth set upon the branchial arches, occur in a great number of 

 fishes,* notably those living on animalcules only. Having been led 

 to suppose that such appendages belong to certain great Sharks, Dr. 

 Steenstrup has been fortunate enough to find a remark made by 

 Gunnerus relative to the Pelerin, dated more than a century ago, 

 and so exactly descriptive of this organ that there can be no 

 doubt of its identity. Thus he has been able to show that other 

 authors also have observed that there was such an apparatus in 

 the Pelerin, although the indications are so incomplete that 

 without Gunnerus' description it would be impossible to under- 

 stand them. 



With this description by Gunnerus, and corresponding indica- 

 tions by other authors — for example Low, Pennant, Mitchell, and 

 R. Foulis — Steenstrup has arrived at the following conclusions : — 



1. The Pelerin {Selachus maximus, Gunn.) or Basking Shark 

 has the interior of the mouth furnished with a fringe or branchial 

 strainer of a special character, as a little beard-like apparatus, 

 with rays 5 or 6 inches long, and resembling that of Balcena, 

 This strainer is situated along the enormous branchial openings 

 of the animal, and takes the part of a sieve to strain the food. 



2. From this branchial fringe come (as Gunnerus' description 

 has enabled us to see) the beard-like apparatuses which have 

 been long preserved in the Museums of Copenhagen, Kiel, 

 Christiania, and Frondhjem, and which Professor Hannover has 

 studied and described in this above-mentioned memoir, in the 

 K. D. V. Selsk. Skrifter, 5 ser., vol. vii., 1867. 



* Dr. Andrew Smith found the branchial openings in the mouth of Rhino- 

 don typicus guarded with a cartilaginous, sieve-like apparatus for straining 

 fmimalcules from water ejected through ^the branchial canals.— ///ms^. Zool. 

 S. Africa, Pisces. London, 1849. 4to. 



