70 



the rows of hooks (toii), in all probability all the specimens 

 pertain to the genus Dasybranchus, those devoid of branchiae 

 having either retracted or lost them. 



Dasybranchus caducus, Grube, 1846. 



1846. Diisxnuilliis caducus, Grube, Archiv f. Naturges, 1846, 

 p. 166, Tab. V. figs. 3, 4. 



1885. Dasybiriiiclnts, sp. (caducus \ Mcintosh, Ann. "Challen- 

 ger," p. 290, PL XLV., figs. 13, 14, PI. XXI Va, fig. 17. 



1887. DasyhiancJiHS caducus, Eisig, Capitell, Nap., p. 823, et 

 ubique, Taf. 16-23. 



The examples vary from 90-170 mm. in length, and the largest 

 has a diameter at its widest part of 7 mm., a size considerably 

 exceeding that of the European specimens, though not much 

 larger than the Japanese form found by the naturalists of the 

 " Challenger." 



The conical snout resembles that of Xotoniastus, and the 

 number of distinctly bristled segments of the anterior region is 

 13. The bristles are long and slender, with a filmy margin 

 indicating the presence of narrow wings. 



The dense rows of minute hooks are similar in structure to 

 those of Notoiuastus, having a main fang and several small 

 points above it, but the shaft appears to have a more distinct 

 dilatation, and the larger wings are united distally so as to form 

 a kind of hood. 



The branchia' occur only on the posterior part of the bod}' — 

 as small tufts of simple or slightly branched filaments arising 

 on each side of the ventral pads, and thus are comparatively 

 near each other. The ease with which the branchia* are retracted 

 or lost accounts for their varied appearance. Those newly 

 reproduced are short and simple, the older forms are more or 

 less branched and larger. 



There is little to distmguish this form from the European. 

 In all essential respects it corresponds both generically, and so 

 far as can be at present observed specifically also with Dasy- 

 branchus caducus, Grube, a form which has been found at 

 Madeira and other parts of the Atlantic, in the Mediterranean, 

 in the Indian and Chinese seas and in the Pacific. 



The HyboscoU'x lougiscta of Schmarda* is probably the same 

 form — procured at Table Bay. 



* Neue wirb. Thicre, I. ii., p. 54, Taf. XXVII. fig. 211. 



