On Steno cypris Ohovreuxi. [ { 



I will now proceed to a more detailed description of 

 the above-mentioned parts. 



The eye (see PI. 1, fig. 3), which undoubtedly, both as 

 regards place and structure, corresponds to the ocellus in other 

 Eutomostraca, is of a rounded quadrate form, and contains 

 a very dark pigment. Its lateral faces are highly refractive, 

 exhibiting in the living animal a very brillant iridescent 

 lustre, and are apparently each divided into two facets. The 

 eye is to a certain extent movable, permitting of a slight 

 revolving motion accomplished by the aid of 2 thin muscles 

 joining it on each side from behind. 



The superior antennæ (PL 2, fig. 1) are each composed 

 of a thick and muscular basal part and a narrow, multi- 

 articulate terminal part or flagellum. The basal part issues 

 from the front part of the body by a broad base, and has 

 the upper face vaulted, the lower nearly plain. It is 

 composed of 2 joints, the proximal one being much the 

 larger, and strengthened by several chitinous stripes 

 anastomosing with each other. From about the middle of 

 the upper side of this joint issues an anteriorly curving 

 simple bristle, and at the end below, two other consider- 

 ably longer reflexed setæ are seen to extend. The rather 

 short and narrow distal joint is only provided with a very 

 small bristle anteriorly, and would seem to be rather firmly 

 connected with the proximal joint. The flagellum, or terminal 

 part of the antennæ, is nearly of the same length as the 

 basal part, to which it is very movably articulated, but is 

 much narrower, and subcylindric in form. It is divided into 5 

 well-defined articulations, the 1st of which is much the 

 largest. From the end of the articulations issue long setæ, 

 forming together a dense brush. It is, however, not easy 

 to count the setæ, as they generally lie very close together; 



