198 JOURNAL OF CONCHOLOGY, AOL. 10, NO. 7, JULY, I902. 



and I am the mure anxious to make the explanation which follows 

 because in an earlier work ['86, p. 34] I adopted a view which I now 

 feel to have been erroneous. First, as regards the specific name, 

 which is taken from Lamarck [1799, p. 13]. His Loligo sagittata is 

 stated to exist in two varieties, of which the first (called "a") must 

 naturally be regarded as typical. The description certainly agrees 

 better with the form under consideration than with any other, notably 

 in regard to its dimensions and the length of the tentacles, but the 

 identification is rendered certain by the reference to two figures in the 

 great work of Seba [1761, vol. 3, pi. 4, figs, i, 2], the suckers extend- 

 ing nearly the whole length of the tentacles, being quite diagnostic. 

 Thirty years later the great Italian anatomist, delle Chiaje ['29, vol. 4, 

 p. 161, pi. 60] gave the same form the name L. fodarus, which was 

 adopted by d'Orbigny, and after him by Jeffreys. D'Orbigny still 

 further confused the matter by affixing Lamarck's name (^sagiitata) to 

 a quite different form, as we shall see later. 



Next, as to the generic name under which this species ought to be 

 ranged : The genus Loligo was first dismembered by d'Orbigny ['35, 

 p. 45], and the form under consideration, along with several others, 

 placed in the newly-created genus Ominastrephes. Subsequently this 

 genus was in its turn broken up by Verrill ['8oa, p. 223] and by Steen- 

 strup ['80]. Verrill erected a genus, Sfhenoteuthis, which included 

 one of d'Orbigny's original species {O. bartrainu) and two others 

 {O. megaptera and O. pteropus) ; he therefore left the Z. sagittata of 

 Lamarck in the restricted genus Ominastrephes. Steenstrup, on the 

 other hand, created the genus Todarodes for our present species, and 

 left O. bartrainii in the restricted genus Ommastreplies. In deciding 

 which of these two courses is to be followed, we must refer to the rules 

 drawn up for zoological nomenclature. The first of those which apply 

 in the present instance is that if the author of a genus has indicated a 

 particular species as its type, that species must remain in the genus if 

 at any future time other generic groups are separated from it. The 

 second is that in cases where this rule cannot be applied, the opinion 

 of the author who first divides a genus is to be adopted. We have, 

 therefore, to enquire in the first instance did d'Orbigny clearly indi- 

 cate any particular species as the type of his genus Ominastrephes ? 

 D'Orbigny's own words ['35, p. 47] are as follows: — " Parmis les 

 especes connues jusqu'a present, ou peut compter le Loligo sagittata 

 Lam., dont les bras pedoncules soient couverts de ventouses sur toute 

 leur longueur ; le L. Onalaniensis Less. ; le Z. brongniartii Blainv. ; le 

 Z. piscatorum Lapil. ; le Z. bartramii Les. ; le Z. illecebrosa Les. ; le 

 Z. Vanicoriensis Quoy et Gaim., et probablement le Z. pelagicus Bosc." 

 It is true that he does not specifically mention a type, but in default 

 of other evidence it would be natural to suppose that he regarded the 



