DEFORMITY OF OS TEXIS IN A SEAL. 251 



16. Deformify of Os penis in a Seal (Phoca caspica Nilsson). 

 13y ISkrgius Alpheraky *. 



[Received October 5, 1917 : Read November 20, 1917.] 



(Text-figure 1.) 



My friend Mr. T. IST. Arnold, our well-known ichthyologist, 

 has kindly lent me for description an abnormal os jjeiiis of an 

 adult Phoca caspica ho himself shot a few years ago on the 

 Caspian Sea. 



This abnormality is eviilently due to an accidental fracture at 

 about the first third part of the total length of the bone. That 

 the bone has here been broken in some way, and has agaiti 

 united with the portions in a distorted position, can clearly be 

 seen from the accompanying drawing, made by my son Dmitry 

 Alpheraky. The drawing shows the bone from above, and as it 

 ii) very exact in form and size, I think it gives a better idea 

 of the malformation than could be given by any amount of 

 description. 



Text-fioure 1. 





The fractured part is so strongly and solidly united with the 

 main part of the bone, that the fracture must have taken place a 

 long time prior to the animal's death. 



It is difficult to find a satisfactory explanation of the cause of 

 such a fracture, and Mr. Arnold thinks that it may have been 

 the sequel of some violent movement of one of the animals during 

 the act of copulation. 



As far as Mr. Arnold remembers, the penis outwardly had no 

 signs, or scars, to show that anything was amiss inside, and 

 the deformity was discovered only during the cleaning of the 

 bone. Tills was not an easy thing to do, as the apical part of the 

 bone had the cavernous integument round it sti'ongly adherent. 

 This apicil part of the bone has now a very rough, porous, 

 uneven surface, showing that the erectile tissue had been deeply 

 embedded. 



* Communicated bj' Mr. 0. Thojias, P.R.S. 



18^ 



