80 ME, W. K. BROOKS ON LUCIFER: 



the fourth abdominal segment, and the anal spots are large, with a dull red tinge. 

 The spots on the carapace disappear at the end of the Zoca series. 



The Mastigopus stage. 



After the next moult the larva (Plate 7, fig. 60) assumes a form which is essentially 

 like that of the adult, but with numerous slight differences, the most important of 

 which are the shortness of the nagellum of the first antenna and the absence of 

 the neck or elongation of the carapace. In these respects, as well as in the number, 

 character, and relative size of the appendages, it now agrees very closely with the young 

 Sergestes or Mastigopus. 



The size of the thorax is reduced, while the abdomen has grown larger and longer. 

 The exopodites of the maxillipeds and first three pairs of pereiopods have disappeared, 

 together with every trace of the fourth pereiopod. The abdominal appendages are 

 perfect ; the first is made up of an elongated basal joint, which carries a single terminal 

 branch of about the same length as the basal joint, but pointed and fringed with long 

 slender swimming hairs. The four appendages which follow are each furnished with 

 two terminal branches instead of one, but are similar in other respects. The larva now 

 sheds its skin several times, and grows with each moult ; but the process of change 

 into the adult is, with the exception of the elongation to form the neck, simply a 

 process of growth, as the appendages and somites ah 1 have essentially their adult 

 character. 



A larva about one-fifth of an inch long, two moults after the last Schizopod stage, is 

 shown from the side, magnified about fifty diameters, in Plate 7, fig. GO. The first 

 antenna (A) is a little more than twice as long as the eye-stalk, and consists of a stout 

 three-jointed basal portion, which forms about two-thirds of the total length of the 

 appendage, and a short, thin, two-jointed flagellum. The scale (ex) of the second 

 antenna is only a little longer than the eye, while the flagellum (en) is more than half 

 as long as the body of the animal, measured from rostrum to telson, and is made up of 

 thirteen small joints and two thicker basal joints. 



The carapace has elongated considerably, and the neck (n) makes nearly half its 

 length. The anterior end of the carapace has a dorsal rostrum (R), two much shorter 

 lateral spines (Is), and a very small spine on each side close to the anterior edge and 

 about half way between the rostrum and the lateral spine. The cephalic lobes of the 

 stomach extend into the neck, and reach nearly to the basis of the eye-stalks. The 

 coiled autennal gland (g) has made its appearance. The carapace proper (c) has a pair 

 of anterior spines, but none on its posterior margin. The labrum (L) has a much 

 greater relative size than it had during the Schizopod stages, but its spine disappears 

 at the end of the last Schizopod stage. The mouth parts and thoracic limbs have 

 their adult character, and will be noticed at length in the description of the adult. 

 A reddish -brown pigment-spot has now appeared between the bases of the eye-stalks; 



