ME. E. J. MIEES ON THE IDOTEIDiE. 11 



b. Epimera on the second to seventh segments distinct. 

 * Species large, elongate-ovate ; outer ramus ofurojwda (or 

 02)ercular valves) minute. 

 Joints of the peduncle of the antenna not dilated ; flagelluiu 

 8-14-jointed ; antero-lateral cervical lobes prominent. 



2. G. entomon (Linn.). 

 Joints and peduncle of antennae greatly dilated ; flagellum 



T-S-jointed; antero-lateral cervical lobes not prominent. 



3. G. Sahini (Kroyer) ? 



** Species small, orhiculate-ovate ; outer o-amus ofuropoda at 



least half as long as the inner. 

 Antennae little longer than the antennules ; flagellum about 

 7-jointed; eyes inconspicuous. 4. G. ccsciis (8aj). 



Antennae about twice as long as the antennules; flagellum 

 about 12-jointed. Eyes usually distinct. 



5. G. Tuftsii (Stimpson). 

 Gltptonotus antaecticus. 



Glyptonotus aiitarcticus, Eights, ''Trans. Albany Instit. ii. p. 331, pis. 

 (1833-52) " ; Amer. Journ. of Sci. Sj- Arts (ser. 2) xv. p. 135 (1853), 

 xxii.p.391,pls. ii.,iii. (1856); Ann.SfMag.Nat.Hist.xi. p. 339 (1853). 



The head (according to Dr. Eights, from whose long descrip- 

 tion and figures the following is adapted) is transversely elliptical, 

 its superior surface is ornamented with an imperfectly sculptured 

 ''fleur-de-lis,'" its posterior portion obtusely elevated, producing 

 a marginal rim ; in the middle of the anterior margin there is a 

 small notch. The segments of the thorax are beautifully sculp- 

 tured on their upper surface, and, together with the post- 

 abdominal segments, are each armed with a median, angular, and 

 elongated knob, which, when united, form a prominent dorsal 

 ridge, gradually diminishing in its backward course, and forming 

 a sharp elevated line along the terminal segment, terminating at 

 its extremity in a short and obtusely-pointed spine. The thoracic 

 segments are bordered along their posterior margins by an 

 elevated and continuous marginal rim, extending to the lateral 

 extremities of the shell. The postabdomen is composed of five 

 segments ; the four anterior are much smaller than those of the 

 thorax, but greatly resemble them in form, being ornamented on 

 their superior surfaces with similar insculptations, though but 

 slightly defined ; the fourth segment (as shown in the figure) is 

 much broader than the base of the terminal segment, and its 



