A LUMINOUS SQUID. 267 



during the vicissitudes of migration. If this be supplemented 

 either by slight visible sex differences, or by some chemical or 

 other means of inter-attraction, such an arrangement might be 

 sufficiently adequate to insure the maintenance of the species. 

 Further field observations with this point in mind would doubtless 

 yield some valuable and entertaining information. 



At first thought it seems passing strange that so conspicuous a 

 phenomenon has not been observed more commonly. However, 

 for the occurrence of species possessing such habits at stations 

 convenient for observation near the shore there would seem to be 

 required not alone shelter from heavy waves but an abrupt slope 

 from the shore-line to the loo-fathom mark so that the contingent 

 requirement for lateral migration be not too great, or similarly a 

 near approach on the part of the deeper regions of the sea either 

 by the agency of a submerged valley or some other consider- 

 able depression. Such conditions are perhaps not always found 

 in appropriate combination in the regions inhabited by these 

 species. Whatever the said conditions may be, Funchal evidently 

 satisfies them, and so affords nearly ideal opportunity for the 

 study of Abralia veranyi. It is hoped that possibly this will prove 

 by no means the only enoploteuthid squid to be found there. 



Whether the animal occurs in the near neighborhood of 

 Madeira at all seasons of the year, or whether its nightly ap- 

 pearance in summer is but the visible culmination of a more 

 extended series of migrations from much farther afield, is a final 

 interesting problem which must be left for some future deep- 

 sea expedition to solve. 



Acknowledgment is due to Senhores M. O. Perestrello & Fos. of 

 Madeira for the use of the accompanying photograph, and to Sr. 

 de Noronha for the original of the small sketch map appended. 

 A grant from the Rumford Committee has also been a con- 

 tributing factor in the preparation of this report. 



SUMMARY. 



I. Abralia veranyi (Riippell) is a somewhat rarely captured 

 Mediterranean cephalopod, possessing interesting luminous 

 qualities due to the presence of numerous and exceedingly 

 complicated photogenic organs. 



