366 A HISTORY OF RECENT CRUSTACEA 



HasiveJUa, Miers, 1884 (a new name for the pre- 

 occupied CaUjpiura, Haswell, 1881), has the last segment 

 of the pergeon produced into a broad plate or shield over 

 and beyond the pleon. The pleon has a terminal qua- 

 drangular notch, with a squarish lobe within it. The hrst 

 antennae are broad at the base. The type is Hasivellia 

 carnea (Haswell). 



Ancinus, Milne-Edwards, 1840, has the body flattened, 

 the pleon triangular with a truncate tip ; the eyes dorsal 

 instead of lateral ; the first and second gnathopods sub- 

 chelate with long curved fingers ; the uropods with only 

 one branch, which is long and narrow, and, as in Ncesa 

 and Gmivpeco'pea^ does not hug the telson. The single 

 species, Ancinus depressiis (Leach), exhibits considerable 

 diversity in the forms of the limbs of the pergeon. 



Scutuloidea^ Chilton, 1882, has the body not very con- 

 vex, the peraeon much broader than the head, the pleon 

 broadly triangular, emarginate at the apex, and the 

 uropods contiguous to it, very salient, single-branched, 

 consisting of a large squamiform plate. The type is 

 Scutuloidea Qnacnlata, Chilton, from New Zealand. The 

 second gnathopods are longer than the other limbs of the 

 peraeon. 



Flcbkartlirium^ Chilton, 1882, has the body much de- 

 pressed, with the side-plates of the peraeon greatly ex- 

 panded, the first pair produced forward at the sides of the 

 head, and the seventh pair backwards nearly to the ex- 

 tremity of the uropods. The two basal joints of the first 

 antennae and the third and fourth joints of the second are 

 expanded, enclosing^ll the front of the head. The pleon 

 is rectangular, with the uropods sub-terminal, the outer 

 branch short, apically dilated. Plakarthium typicum, 

 Chilton, found on the seaweed EMonia radiata^ in Lyttel- 

 ton Harbour, New Zealand, ' afibrds a very good example 

 of protective resemblance, for the body being very flat and 

 of a brown colour can scarcely be distinguished from tl^e 

 seaweed, to which it closely adheres.' Its position among 

 the Sphaeromidae is somewhat doubtful, if it be the case 



