68 T. V. HODGSON. 



AUSTROSIGNUM GLACIALE. 



(Plate X., fig. 2.) 

 Specific characters : 



Head small, rounded ; eyes not well developed, at the extremity of slender peduncles. 

 First four segments of the mesosome subequal in length, and separated from the posterior three 

 by a distinct " waist " ; the posterior three diminishing in diameter, and but slightly curved. 

 Urosome a pointed oval, rather elongate, with minute pretermiual uropoda. 



The cephalosome is small, resting in a shallow crescentic depression of the first 

 segment of the mesosome, which has nearly twice its diameter. Near the postero- 

 lateral margins arise long slender stalks which bear small, apparently simple eyes. 

 These stalks are unjoin ted prolongations of the cephalosome, and in length they are 

 nearly half its diameter. 



Of the mesosome the third segment is the largest and widest ; between the 

 epimera of the fourth and fifth there is a distinct space, and the last three progressively 

 diminish in diameter and increase in curvature, but not to any great extent. The 

 epimera of all are rounded. 



The metasome comprises a small joint and a urosome, which may be described as 

 ovoid but attached by a short and broad peduncle. 



The uropoda are very small, biramous ; the basal joint is extremely short, and 

 each branch consists of two minute joints ; the endopodite is the most slender and is 

 no more than a very small joint and spine. 



A few setae are scattered about the margin of both mesosome and metasome. 



The first antenna is short, comprising a peduncle of two rather elongated joints, 

 the second being the larger. The flagellum is about as long as the peduncle. 



The second antenna has a peduncle of six joints, the first two are short and stout ; 

 the third is about as long but more slender ; the fourth very short, only forming a 

 bend in the appendage ; the fifth is rather long, and the sixth longer still ; the 

 flagellum is short, but little longer than the last joint of the peduncle. 



The mouth parts are quite normal in structure. The mandible consists of a stout 

 process with a small but strong tooth at its anterior border ; the molar process is long 

 and slender and armed with five teeth, of which one, the second, is larger than the 

 rest ; there are also several stout setose spines just behind this terminal group. The 

 palp is long, three-jointed. 



The first and second pair of maxillae do not present any special features unless 

 it be that some of the terminal spines on the outer part of the outer lobe are really 

 strong teeth ; the lobes of the second pair are finely serrated. 



The maxilliped is of normal appearance ; the straight distal edge of the 

 masticatory lobe bears some half-dozen stout setae, which are finely serrated. Two 



