ARCTURUS LONGTCORNIS. 367 



The first three segments of the pereion are very short, 

 with a produced lateral margin (representing the coxae, 

 or first joint of the legs, and) concealing the base of the 

 legs, the first pair of which are alike in form, but shorter 

 than the others, and evidently perform the office of an 

 extra pair of foot-jaws; indeed, from the manner in which 

 this, as well as the three following pairs of feet, are carried 

 over the mouth, it is probable that they are all employed 

 rather as such than as locomotive organs. The very slender 

 structure of these three pairs of legs, which are all formed 

 alike and are strongly ciliated within, is also confirmatory 

 of this opinion. The first pair of legs are also ciliated, 

 the cilise arising in double rows, and being often bearded, 

 as is also the case with the three following pairs, in 

 which, however, only two of the hairs situated near the 

 extremity of the penultimate joint are thus bearded. 



The fourth segment of the body is very long, occupy- 

 ing more than one- third of the whole length of the 

 animal, and being perfectly cylindrical in the males, in 

 which sex it is without any orifice or inferior lamellae, 

 and is the narrowest part of the body ; but in the female 

 it is as wide as the head, and furnished beneath with two 

 thin membranous plates, lapping over each other, and 

 serving as an envelope for the eggs, which are of a red 

 colour and kidney-shaped. The fourth pair of legs are 

 attached below the anterior angles of this segment. The 

 three succeeding segments are short, rounded at the sides, 

 and respectively furnished with a pair of strong short 

 legs, well formed for prehension, having the last joint 

 terminated by a bifid hook. These legs are not ciliated, 

 and have a backward direction. 



The tail, seen laterally, appears to consist of only two 

 segments, of which the first is almost globose, and the 

 second oval, terminating in a strong spine; seen from 



