18S SEPTA. 



resemblance to the shells of those species of which the animal is 

 known. Steenstrup believes that the species, being exclusively 

 littoral, have not any extended geographical distribution, and 

 therefore probably many undescribed species exist ; at the same 

 time he carefully warns naturalists not to confound the consid- 

 erable diflerences which are really individual only with those of 

 specific importance — advice which is equally pertinent to the 

 cephalopods in general. 



Dr. J. E. Gray thus groups the shells of the Sepiae with refer- 

 ence to the figures in Ferussac and d'Orbigny's monograph : — 



* Shell obloDg. 



f Apex very bluut. S. officinalis, S. latimanus. 



f f Apex produced. S. vermicitlata, S, Rouxii, S. Rappiana, 



S. Bertheloti, S. Hierrbdda, S. aculeata, S. Blain- 



VILLII, S. ROSTRATA. 



Iff Apex very bluut and produced. S. tuberculata, S. papil- 



LATA, S. MAMILLATA, S. LePEBREI. 



* "" Shell oblong, produced behind. S. inermis, S. Sinensis, S. 



ornata, S. microcheirus. 



* * * Shell very narrow behind, and arched. 



f Apex simple. S. australis, S. Rupellaria, S. Capensis, 



S. Orbignyana. 

 f f Apex dilated. S. elegans, S. elongata. 



The above grouping may serve to approximately determine 

 the species of the Sepiostaires, but it does not correspond with 

 the external relationships of the animals, as shown b}' Dr. Gray's 

 synopsis, which is herein adojited. 



§ Sessile arms with small ecjual cups, all in f oar regular series. 

 '■■ Tentacles with five or six series of unequal-sized cups. 

 S. OFFICINALIS, Linn. PI. 86, figs. 390, 391 ; pi. S7, fig. 389. 



Body ovate, depressed, smooth ; head with two elongated, and 

 some smaller beards above ; arms short, strong, unequal, order 

 of length 4, 3, 2, 1, ring of cups smooth, entire ; clubs of tenta- 

 cles much enlarged, with six alternating lines of cups, the five 

 central cups much larger, rings of the larger cups smooth, of the 

 smaller ones toothed. Black purple, with darker cross bands, 

 forked, and with small white spots on the side. Shell oblong, 

 broadly lanceolate without the cartilaginous fringe, white except 

 on the back, which is faintl}'^ tinted with flesh color; back hard. 



