180 



'TERRA NOVA" EXPEDITION. 



Adult. $ 8-45 mm. by 7-7 mm. (Fig. 2a.) 



First Antennae. — The second and third segments bear over twenty bristles on the 

 dorsal surface. 



Second Antennae. — The basal joint of the secondary branch bears eight or ten hairs, 

 second joint five hairs. 



Mandibles. — First sensory joint bears numerous hairs on ventral edge. Second 

 joint about ten. Third joint very many. 



Cleaning foot. — Well developed. 



Furca. — Three pairs of stout, finely serrated spines, followed by about nine pairs of 



plumose bristles. 



Stage II. ? 2'5 mm. by 2-1 mm. (Fig. 2b.) 



First Antennae. — Second, third and fourth segments each bear one large plumose 

 hair or bristle on the dorsal surface. 



Second Antennae. — The basal joint of the secondary branch bears one or two hairs, 

 second joint hairless. 



Mandibles. — First sensory joint bears about sixteen hairs, second joint two, 

 third joint many. 



Cleaning foot. — Undeveloped. 



Furca. — Three pairs of more slender, finely serrated spines, followed by three or 

 four pairs of plumose bristles. 



Stage III. $1-9 mm. by 1-65 mm. (Fig. 2c.) 



First Antennae.— Third segment alone bears a single hair. 



Second Antennae. — Secondary branch hairless. 



Mandibles. — First sensory joint bears five hairs, second joint two, third joint about 

 twelve hairs. 



Cleaning foot. — Undeveloped. 



Furca. — Three pairs of spines, the third not serrate, imperfectly separated from 

 furcal plate, and followed by a few simple hairs. 



There may be an older stage between Stage II and the adult, which is not 

 represented by the specimens obtained. 



Adult. 8-45 x 7' 



