Manchester Memoirs, Vol. I. (1906), No. 14. 



XIV. The species of Ctenopteryx, a genus of 

 Dibranchiate Cephalopoda. 



By Dr. J, H. AsnwORTH and Dr. W. E. HOYLE, 



Read May Sth, igo6. Received for pziblication Jjily 2.^th, igob. 



The genus under discussion was created in 1890 by 

 Dr. Appellor for a small Cephalopod from Messina, only 

 15 mm. in length, and characterised as follows : — 



Ctenopteryx Appellof ('90, p. 3). 

 The fins consist of a series of muscular threads, united 

 down to the base by a very thin, transparent membrane, 

 so that each fin has a comb-like appearance. The mantle 

 connective consists of a tract of cartilage on either side 

 of the base of the funnel, wider behind, and with a very 

 narrow groove down its middle, corresponding to which is 

 a cartilaginous ridge on the inner side of the mantle. 

 Only two pairs of siphonal adductors are present, of which 

 the upper pair are visible from without ; an external 

 muscle from the funnel to the head, as seen in Ommas- 

 trephes, is absent. The ocular opening is drawn out 

 forwards into a pointed sinus, so that it assumes a pear- 

 shaped appearance. There is no clearly defined funnel 

 groove ; the funnel has a valve. 



The following forms have been referred to this genus 

 by various authors : — 



Ctenopteryx fimbriatiis, Appellof (type). 



Ctenopteryx cyprinoides, Joubin. 



Calliteuthis nevroptera, Jatta. 



Sepioteuthis sicula, Riippell. 

 We propose to discuss these identifications seriatim. 



August 14th, igo6. 



