128 VERANY AND VOGT ON THE HECTOCOTYLI 



We were in despair, when, in April of this year, the males of 

 Tremoctopus Carena appeared all at once in very great numbers. 

 We give in the following pages the results of our common 

 studies, observing, however, that M. Verany especially occupied 

 himself with the zoological portion, whilst M. Vogt principally 

 took charge of the anatomical investigations. 



I. Zoology, 

 Tremoctopus Carena. Tremoctopus Carena, Verany. Poulpe 



Carena, Octopus Carena, Verany. Mem, de V Academic Roy ale 



des Sciences de Turin, 2^ serie, t. i. pi. 2. 



Monographic des Cephalopodes de la Mediterranee, p. 34 & 128, 

 pi. 14. figs. 2 & 3 ; pi. 41. figs. 1 & 2. 



Body sac-like, provided with a constrictor apparatus. Head 

 compressed ; eyes large and projecting. Arms unequal : first 

 and fourth pair longest. Acetabula pedunculated. Funnel very 

 large ; two aquiferous apertures. 



Tremoctopus Carena, male (PL I. fig. 3. 4.). 



Body sac-like, oval, slightly acuminated behind, very smooth. 

 Branchial aperture wide, cleft as far as the orbits. Constrictor 

 apparatus formed by a fleshy appendage having the form of an 

 oblique hook, situate upon each side at the base of the funnel, 

 and a horizontal cleft like a button-hole, in the thickness of the 

 skin upon the internal margin of the body. 



Head moderate, wider than deep, being compressed by the 

 first pair of arms w^hich arise at the level of the orbits ; lateral 

 part of the head occupied almost wholly by the orbits ; inferior 

 portion wholly covered by the funnel. 



Eyes lateral ; eye-balls projecting and flattened, wholly covered 

 by a transparent membrane which is continuous with the skin ; 

 this membrane is pierced by a slightly contractile circular aper- 

 ture, through which the crystalline lens presents itself wholly 

 without covering. 



Arms conico-subulate, unequal ; the fourth pair is the longest 

 and measures about two and a half times the length of the body; 

 the first is shorter than the fourth and measures only twice the 

 length of the body ; the second is only half as long as the fourth 

 pair ; the left arm of the third pair is a little shorter than that of 

 the second pair ; the right arm of the third pair is hectocotyli- 



