92 Miscellaneous. 



zoologists a little sepiau which Captain Andrea has brought me from 

 Table Bay, at the Cape of Good Hope, and which I now publish as 

 a distinct genus, under the name oi Hemisepius typicus. Bearing in 

 mind, on the one hand, the common characters which all known spe- 

 cies of Scpice present, as well as the modifications that these charac- 

 ters often undergo according to the species, and, on the other hand, 

 the differences due to sex, age, and season, that a long study of the 

 Cephalopoda * has enabled me to demonsti-ate in individuals of the 

 same species, I establish provisionally, until the discovery of new 

 forms, the three following characters for my Hemisepius, considered 

 as a genus. 



Hemisepius., which in other respects completely resembles a Sepia, 

 has (1) a mantle which bears on its ventral sui'face deep pores, 

 which in the H. typicvs are disposed in two rows of twelve pores 

 each, one on each side ; these pores are situated in little nipples, 

 and united with one another by a little longitudinal groove ; (2) a 

 test which is only half-developed (whence its name) ; the very rudi- 

 mentary calcareous partitions do not cover the anterior portion of 

 the dorsal plate, and their anterior margin is not parallel to the 

 corresponding margin of that excessively thin plate ; (3) on the 

 eight arms only two rows of suckers, which differ besides from those 

 of the true Sepice by their much depressed and nearly discoidal form. 

 Even without the presence of the pores on the lower surface of the 

 mantle, either of the two latter characters, if we consider the gene- 

 rality of the known species of the genus Sepia, would have sufficed 

 to induce the establishment of a new genus; but as similar pores, so 

 far as I know, are only found in the genus Sepioidea, and are there 

 accompanied by characters which render its separation from the 

 genus Sepiola quite natural, I have thought that I ought to attach 

 all the more importance to their appearance in Hemisepius. 



The individual put at my disposal being small (it only measures 

 53 millimetres long), it was important to get rid of any idea that the 

 animal in growing might lose the characters which distinguish it 

 from all the known Sepice, as to the feeble development of its test 

 and the peculiar form of its suckers &c. I therefore show that this 

 individual, which is a female and would perhaps have grown larger, 

 may be regarded as adult. In fact, not only is it fit for reproduction, 

 but it has already received spermatophores in the very peculiar situ- 

 ation where they are fixed on all the Sepia;, the Sepiioteuthes, and 

 the Loligines, as I showed for these three genera, eighteen years ago, 

 in my memoir on the hectocotylized arms of the male Cephalopoda in 

 general. I reproduce here the following passage relating to these 

 remarkable characters, which have been far too much neglected up 

 to the present time by the naturalists of some countries : — 



" The right of employing, as we have done here, the hectocotylized 

 arm as the check of a natural grouping of the Cephalopoda, resides 



* These differences between individuals of the same species have gene- 

 rally passed unrecognized ; and from this a deplorable confusion in the de- 

 termination of the species and genera and even of the families has often 

 resulted. 



