24S 



DISCOVERY REPORTS 



Didymochelia spongicola, Brnrd. (Fig. 156). 

 Barnard, 193 1, p. 429. 



Occurrence: St. 142. South Georgia. 1 $ 4 mm., from sponge. 



Description. Head with scarcely any median point, but anterior margin rather 

 deeply sinuous around base of antenna 1, antero-inferior angle rounded. No trace of 

 eyes. Peraeon dorsally rounded; postero-inferior angles of segments 5-7 slightly pro- 

 duced, subacute. Side-plates 1-4 quadrangular, lower margins rounded, 4 not deeply 

 excavate; 5 bilobed, the anterior lobe slightly deeper than the posterior; 6 and 7 

 posteriorly produced in acute points. Pleon segments 1 and 2 dorsally rounded, 3 with 



Fig. 156. Didymochelia spongicola, Brnrd. a. General view. b. Upper lip. c. Lower lip. d. Mandible, with 

 cutting edge and secondary cutting plate further enlarged, e. Maxilla 1 . /. Maxilla 2. g. Maxilliped. h. Side- 

 plate 1 and gnathopod 1. i. Gnathopod 2. /. Peraeopod 5. k. Uropod 2. /. Telson and uropod 3. 



a small upturned triangular carinal tooth on hind margin ; 4 with slight transverse de- 

 pression, posterior margin raised into a transverse tooth; segments 5 and 6 very short; 

 postero-inferior angles of segments 1-3 ending in short acute points. Telson transverse, 

 broader than long, rounded posteriorly, a short stout spine on each side of the feebly 

 concave distal margin. 



Antenna 1, 1st joint stout, flagellum 8-jointed, 1st joint longest and bearing a brush 

 of setae, accessory flagellum 4-jointed. Antenna 2 slender, flagellum 8-jointed. 



Mouth-parts prominently projecting, though not styliform. Upper lip elongate- 

 triangular, apically narrowly rounded. Lower lip without inner lobes, outer lobes 

 apically subacute, mandibular processes very small. Mandible, cutting edge obscurely 



