34 bulletin: museum of comparative zoology. 



Family :NrASTIGOTEUTHIDAE. 



Mastigoteuthidae Verrill, '81 a, p. 100, 



MASTIGOTEUTHIS. 

 Masligoteuthis Verrill, '81 a, p. 100. 



33. Mastigoteuthis dentata, sp. n. 



(Plate 6, Figs. 8-11.) 



Habitat. — Station 3400; E. of Galapagos Islands; March 27, 1891; lat. 

 0°36'S., long. 86°46' W., 1322 fothoms; temperature, surface 81°, bottom 

 36°; light gray globigerina ooze ; one specimen 9) ^f>. 7956. [H. 102.] 



Station 3394; off Cajje Mala; March 10, 1891 ; lat. 7° 21' X., long. 79° 35' 

 "W., 511 fathoms ; temperature, surface 73°, bottom 41. °8 ; dark green mud ; 

 one specimen <J, No. 7957. [H. 45.] 



This species differs from Mastigoteuthis agasdzi (Verrill, '81 a, p. 100) in the 

 fact that the horny rings in the suckers of the arms are furnished with teeth 

 (Plate 6, Fig. 8), whereas in that species they are smooth. 



It differs from M. hviinana Lbnnberg ('97, p. 605) in the fact that the 

 ventral arms are thicker and not thinner than the others and have the 

 suckers normally disposed. It agrees with this, however, in the denticulation 

 of the homy ring of the suckers. Lonnberg is mistaken when he says that 

 the horny rings on the arras of the "Challenger" specimen had pointed 

 teeth. The " Challenger " specimen was only a fragment of a tentacle and 

 therefore gave no information regarding the suckers of the arms. 



The two sexes show an interesting difference in the form and proportions of 

 the bod}' and fin, the latter being two-thirds the length of the mantle in the 

 male and only about two-fifths in the female ; the body too is more conical 

 in the former, more cylindrical in the latter. The absolute dimensions of the 

 male are much smaller, but there is no evidence to show whether the speci- 

 mens are full grown. One of Verrill's male specimens attained a length 

 of 232 mm., wiiich is intermediate in size between the two e.xamples here 

 described. 



The general arrangement of the organs seen on opening the mantle-cavity is 

 6howu in Plate 6, Figs. 10, II. 



Dimensions. 



7957 cf 79569 



mm. mm. 



Lcnptli, totnl (without tentacles) .... 180 290 



Enil of bofly to mantle-margin 72 140 



End of boily to eye 81 155 



Brondtli of body 17 30 



Brcndtii ofl.cad 17? 26? 



LonRth of fin 48 60 



Breadth of fm 62 75 



