PACKARD.] 



DEVELOPMENT OF BEANCHIPODID^. 



429 



segments indicated show a diameter of O.SS"^'" on tlie broadest part of 

 the body, at the first pair of bran<}hipeds. 



Streptocephalus texanus 

 in the same stage of de- 

 velopment (in an aqna- 

 rinm) of branchipeds and 

 segments measures 0.8™"^ 

 in'length and 0.43""" in 



width . Th e first and sec- 

 ond pairs of antennae, of 

 course, are also propor- 

 tionally stouter in Mi- 

 hranchijms. 



The anterior antennae 

 have (in the above stage) 

 three hyaline flagellate 

 bristles of CTo"^"^'! in a 

 length, which, after tLe 

 third moult, are reduced 



nnnciVlA-rnl^UT VK.r^o.—Etihranchipus. nFirst bristle-hook of 23 antennfiof larva, 



i^uuMUCici'Uij . j^„,„ j^j^^, . jj ^jj^ j^j^jjjg when older; d 2fl bristle-hook of 2d antenna 



Shortly before the time of larva- c one of the two middle bristles of mandibulary palpus. 



when the second antennge ^°-^^ '^^^' 



drop their long bristles the first four olfactory hacilU make their appear- 

 ance at the side of the tip of -the anterior antennae. 



The second jxiir 

 of antennoi agree 

 in general with 

 those of BrancJii- 

 pus or Streptocep- 

 halus. There is ~ 

 a basal hook bris- 

 tle first n 1 a i n ■^^^- 56.— Setas of first maxilla of Eubranchipus. 



then ciliate (Fig. 55 «) and then split. Second bristle-hook appears CFig. 

 55 d) to be triangular or rounded exteriorly, and two-edged and ciliate 



Fig. 57. — Anterior antenna of pale Eubranchipus mounted in ffly- 

 cerine osmic acid prep. Prom a specimen with three branchipeds 

 budded, 1st of the latter with a single claw. 



interiorly. The terminal outer branch of the second an- 

 tenna has fifteen long bristles and a terminal shorter one 5 

 the inner or posterior branch has three long and one short 

 bristle. This branch is three-jointed; terminal branch is 

 subjointed. 



First maxilla of adult EubrancM'pus is i)lain, and has 

 thirty-one long, flat, acinaciform bristles or teeth, equally long (Fig. 56.) 



The second maxilla is composed of a narrow, small, basal piece, with 

 two strong, thick si^ines, each finely ciliate. 



