ANCEUS MAXILLARIS. 193 



and articulation to those of the male. We have found no 

 other trace of mouth organs in these developed females. 

 The two succeeding segments of the body are quite dis- 

 tinct, very short, and rounded at the sides, but the three 

 terminal segments are consolidated into a large oval 

 mass covered with delicate membranes, through which 

 the eggs and young are plainly visible ; the black eyes 

 of the latter giving to this part of the body a speckled 

 appearance, and showing at the same time that the 

 arrangement of the young within the incubatory pouch 

 is completely irregular ; and we have never seen the sym- 

 metrical arrangement of the larvas as figured by M. Hesse 

 in the gravid female. The tail (pleon) and its appen- 

 dages resemble those of the male, and the legs do not 

 exhibit any more marked differences beyond being some- 

 what more slender. One of the young extracted from 

 the pouch of the parent, and which attains to more than 

 a third the length of the adult animal before it quits the 

 ovi sac, is represented at the left hand side of the above 

 engraving. 



The state of these animals previous to arriving at com- 

 plete maturity offers several circumstances sufficiently 

 remarkable to account for the larger sized larvae (if 

 we may so term them) having been mistaken for fully 

 developed females. It is this .state which was first 

 described by Slabber and Montagu, and also by Mr. 

 Spence Bate, who confounded it with the adult animal, in 

 the " Annals of Natural History " for September, 1858. 

 The large mass formed by the consolidation of the three 

 posterior segments of the body is of a very elongated 

 oval shape, and in the individuals described by Montagu 

 was of a fine blue colour ; whence the specific name 

 which he applied to it. It varies, however, not only in 

 different individuals, but also in different states of the 



VOL. II. o 



