12 H. J. HANSEN. 



Scut, capensis I observed tliat all scuta (the first one 

 perhaps excepted) are divided b}- a transverse farrow into a 

 very short anterior and a long posterior part; the anterior 

 part is in this species easily distinguished from the articu- 

 lating membrane in front o£ it by its surface, which is 

 adorned with short, irregular, somewhat curved, transverse 

 stripes, while the articular membrane wants such stripes, but 

 is finely dotted. In very extended specimens of other species 

 I have found a similar division of the scuta, but the anterior 

 part is here often scarcely distinguishable from the articu- 

 lating membrane. The species of Scolopendrella possess also 

 fourteen scuta, but the two posterior ones are divided by a 

 transverse stripe of articulating membrane, so that they can 

 easily be counted as four scuta, the anterior part being more 

 than half but scarcely ever quite as long as the posterior 

 one ; the anterior parts are setiferous like the others, but are 

 easily distinguished by their shape; all the scuta, the four- 

 teenth one excepted, are posteriorly produced into two lateral 

 triangular plates of considerable size, those of the last one 

 being somewhat smaller, but the hind margin of the anterior 

 part of the two posterior scuta is transverse without any 

 vestige of triangular plates. In very extended specimens of 

 various species it is observed that the first to the twelfth 

 scuta are divided into a long posterior part and an anterior 

 one, which is a little longer than in the other genus, and 

 generally very difficult or impossible to distinguish from the 

 articulating membrane. 



In Scolopendrella the shape of the posterior triangular 

 plates and their distance from each other differ after a 

 certain rule in the scuta of the same animal; for instance, 

 the plates of the second scutum are always more narrow in 

 proportion to their length and less distant fi'om each other 

 than those of the third scutum (various figures on Pis. 5 — 7) ; 

 the plates of the others arc rather similar in shape either to 

 those of the second or those of the third scutnm, or form a 

 ti'ansition between them. I have found these two scuta to be 

 the most practical to study, and the others are omitted as 



