ARTEMIA. 57 



Anatomy and Pliysiologij, Sfc. — The Artemia resembles 

 the preceding genus so much in anatomical strnctm-e, that 

 it is unnecessary to enter fully into details. The superior 

 antennae in both sexes, and the inferior in the female, are 

 exactly similar to those of the Chirocephalus (t. II, f. 2d). 

 The prehensile antennas of the male (t. II, f. 2 a) differ, 

 however, in two or three respects. They are large, flat, and 

 curved downwards towards the thorax, as in the Chiroce- 

 phalus, and are also divided into two articulations. The first 

 articulation is much more simple than that of the Chiro- 

 cephalus, and has none of the complicated apparatus 

 attached to it which is so remarkable in that genus ; while 

 the conical, antenna-like appendage is firmly attached to 

 its inner edge, and is not moveable. The second joint is 

 flat, broad, bent nearly at a right angle about the middle 

 of its length, and sharp-pointed. 



The two lateral pedunculated eyes and the median 

 sessile, black spot are precisely similar to those of the 

 Chirocephalus, and the organs of the mouth do not differ 

 in any circumstance but in the lip being rather more 

 developed. 



The divisions of the thorax are not quite so distinct as 

 in the Chirocephalus, but they are of the same number, 

 and as each division has attached to it a pair of branchial 

 feet, these organs consist also of eleven pairs, notwith- 

 standing that Latreille, followed by Desmarest, asserts 

 they have only ten. In structm^e they resemble almost 

 exactly those already described in the preceding genus 

 (t. II, f. 2 c) . They gradually increase in length from the 

 first to the sixth, and decrease again from that to the 

 eleventh. 



According to Joly, the abdomen is only composed of 

 six instead of nine articulations. The first has the ex- 

 ternal ovary attached to it in the female and the organs of 

 generation in the male, while the last is by much the 

 longest, and terminates in two short, conical prolongations, 

 furnished at their extremities with a few short hairs. 

 The external ovary is of a somewhat quadrilateral shape. 



