THE CHiETOGNATHA. 



73 



to heflaccida or tenuis, and the general outline is quite different from that of hispida. 

 Elegans is said to be very much like hipimctata, which caanot be said of these specimens. 

 Tlie limitation of the corona ciliata to tlie body sufficiently separates it from, pulchr a. 



There remains a certain number of specimens with more or less hexapterine numbers 

 of jaws and teeth, and of the pliant flabby hexapterine type and proportions. These 

 may include more than one species, but the examples are either so few or so badly 

 preserved that, not having handled as yet large numbers of undoubted hexaptera, I 

 prefer to leave them somewhat vague. So far as the numbers of teeth and jaws are 

 concerned, most of them can be fitted only into hexaptera (d'Orb.), magna (Langerhans), 

 or tricvspidata (Kent). Dr. Krumbach has already expressed his belief that hexaptera 

 and magna are synonyms : with this I agree (so far as is allowable without a comparison 

 of type specimens), at any rate as regards the magna of Langerhans ; whether Grassi bad 

 the same species before him, or not, is hard to say. I incline further to add trlcuspklata 

 as yet another synonym, having before me large specimens from the ' Siboga ' expedition, 

 which by the numbers of the armatvire are tricuspidata, but in other respects agree 

 sufficiently with hexaptera. Kent's original diagnosis of tricuspidata was not adequate : 

 except for the armature numbers, it might be applied to several species, and his figure 

 might stand for an inflated hexaptera ; it has certainly a more apoplectic look than most 

 hexaptera, but the proportions of the body alter at death in very different directions 

 among these less rigid forms, and I have noted a greater difference in general form 

 between two specimens of furcata than exists between Kent's figure of tricuspidata and 

 the ordinary drawings of hexaptera. 



(i.) A few of these specimens are probably attributable to Sagitta ? hexaptera, 

 d'Orbigny, itself. They occurred as follows : — 



Species indeterminatce. 



(ii.) From several hauls came specimens of which the cirrhi were either in excess of 

 those recorded for hexaptera, or were present in very small specimens to the 

 number of eight, the maximum nvunber in the largest hexaptera as yet recorded 

 (if Grassi's magna be omitted). Some of these were probably young furcafa, 

 others may be the young of other species. 



They may be summarized as follows : — 



12* 



