460 Proceedings of the Royal Physical Society. 



subject in question is of importance to naturalists in this 

 district, and because the publication of this note may lead 

 to the correction of a mistaken piece of nomenclature which 

 appears in many of our museums. 



So long ago as 1857 Professor Steenstrup recognised the 

 distinctions between the common species of the North Sea 

 and that of the Mediterranean, and pointed them out in his 

 classic treatise on the Hectocotylus formation,^ from which 

 I quote the passage referring to this matter : — 



"The specific distinctions between Loligo vulgaris, Lamk., and Loligo 

 Forbesii, Stp., are best derived from the form and size of the suckers 

 on the tentacles : in L. vulgaris of the Mediterranean, as described and 

 figured by D'Orbigny and Verany, and also in a form of our coasts 

 which may certainly be regarded as L. vulgaris, these are very large in 

 the two central rows and very small in the lateral rows, so that a trans- 

 verse section of the latter is only half that of the former, and their height 

 only one-third ; whilst in L. Forbesii, Stp. , the suckers of the central rows 

 scarcely exceed those of the lateral rows, either in transverse section or in 

 height ; and, on the whole, it appears as if the club of the tentacle had four 

 series of suckers of equal size. In comparison with the suckers of the arms, 

 the disks of the central rows of the tentacles in Loligo vulgaris are from two to 

 three times as large as the largest disks on the third arm, whilst in L. Forbesii 

 they are scarcely one-third larger. The horny ring in the central rows of 

 suckers in L. vulgaris has only one-half of its circumference finely toothed, 

 whilst the other half is toothless, or only bears a group of 4-5 small 

 blunt teeth (in a northern form these are indeed the only teeth on the 

 horny ring) : in L. Forbesii the ring bears numerous pointed teeth all 

 round, and these are usually larger and smaller alternately. In this species, 

 also, the suckers of the lateral series have the horny ring completely set with 

 teeth of equal size, whilst in L. vulgaris their horny ring has high-pointed 

 teeth in the upper half, and the lower half almost toothless. In colour, 

 also, L. Forbesii is characterised by having the colour-sacs united into linear 

 spots on the anterior part of the sides and also down the ventral surface. 

 These long, dark markings, and the nearly uniform size of the tentacular 

 suckers, consequently distinguish this species from L. vulgaris at the first 



The species thus recognised and defined by Professor 

 Steenstrup is very common on our coast, and is continually 

 brought in in large numbers by the Newhaven trawlers, and 



^ K. dansJc. VidensTc. Selsk. Skrifter, R»kke 5, Bd. iv., p. 189, 1856. I 

 quote from Mr Dallas' translation, Ann. Mag. Nat. Hist, ser. 2, vol. xx., 

 p. 84, 1857. 



