412 M. E. Hesse on the Pranizse and Aneei. 



Tht generative organ is situated at the extremity of the thorax, 

 above the abdomen : it consists of a long penis, showing 

 throughout the course of the canal which traverses it. This 

 penis is in the median line of the thorax ; its base is formed by 

 the first branchial feet, and it is protected above by a sort of 

 cup formed by a fold of skin. This cup seems to be destined 

 to receive the laminae of the branchial false feet when they are 

 raised over the thorax, and by this combination the generative 

 organs are completely protected. 



This structure is common to all the species, and the organ 

 only varies in form. Thus in Anceus Manticorus the penis is 

 greatly developed, and consists of a long erectile tube diminishing 

 from the base to the apex, with a central canal traversing it from 

 end to end. It is truncated at the apex, which is surrounded by 

 a thickened portion notched in the middle, the extremities of 

 which form two valves or excitative organs. In Anceus Briva^ 

 tensis the tube is not so long, and appears to be articulated and 

 capable of being invaginated in the lower parts ; the extremity 

 is also furnished with two lateral prehensile or excitative organs. 

 In Anceus Trigli the penis is short, tubular, and inflated in the 

 middle. 



Structure of the Female Ancei. 



The female Ancei are so different from the males that, without 

 tracing their transformations, their connexion could not have 

 been suspected. The head, instead of being of considerable 

 size, as in the males, is very small, and is moreover deprived of 

 the two large mandibles ; the thorax, instead of being cylindrical 

 and elongated, formed of distinct segments and divided into two 

 parts by a constriction, is oval, flattened at the sides, inflated in 

 the middle, and as it were deformed by the great quantity of 

 ova which it contains. 



The head, seen from above, is globose in the centre, flattened 

 at the margins, broad at the base, and truncated at the apex. 

 It has no apparent neck, but is deeply inserted between the two 

 anterior processes of the thorax. Transverse lines in the thorax 

 indicate its division into five segments ; all round the thorax is 

 a broad margin, which serves for the attachment of the five pairs 

 of legs. The eyes are pretty large, and placed at the origin of 

 the antennae. 



Seen from beneath, the head presents, first of all, two footjaws 

 of the first pair, which originate beneath the eyes, and consist 

 of four broad joints of equal length, but diminishing in width 

 from base to apex. The last joint is rounded at the end, and 

 bears some hairs. These two footjaws meet in the median line 

 of the head, and pass its apex a little. Beneath these is the 



