254 DISCOVERY REPORTS 



Tergum with a strongly developed articular ridge, and a spur near the basi-scutal 

 angle. Crests for depressor muscles indistinct. 



Measurements: the carino-rostral diameter is lo mm.; the height is lo mm. 



Mouth Parts: the mouth-parts are described by Hoek (1883) and partly figured. For 

 comparison, figures of the Discovery specimen are given. Labrum of the Chthamalid 

 type with a slight inward flexion in the middle. Free edge with hairs, but without teeth, 

 a feature pointed out by Hoek. Palp long and rounded at the end, with feathered 

 bristles. Mandible with four teeth (two to four with additional teeth) and an inferior 

 angle divided into three small teeth (quite as stated by Hoek (1883)). Maxilla I with 

 a broad notch in the upper part with smaller bristles. The lower part projects, and 

 bears spines of about the same size. Maxilla H is bilobed as in Chthatnalus. 



Number of segments of the cirri 

 Cirrus I II III IV V VI 



Segments 9 12 13 15 18 20 24 26 28 30 30 31 



The number of the segments are smaller than in Hoek's specimen, as this individual 

 is younger. Cirrus I with unequal rami. Cirrus H with slightly unequal rami. Those 

 following with nearly equal rami. 



Genus Balanus, da Costa, 1778 



Balanus maxillaris, Gronovius, 1763. 



Gronovius, 1763, Zool. Gronov. Iconogr. v, PI. xix, figs. 3, 4. 



Lepas cyUndrica, Gmelin, 1790, Syst. Nat. p. 3213. 



Balanus capensis, Ellis, Darwin, 1854, Monogr. Balanid. p. 209; Gruvel, 1905, Monogr. Cirrhip. 



p. 218. 



Balanus maxillaris, Pilsbry, 1916, Bull. U.S. Nat. Mus. No. 93, p. 77; Barnard, 1924, Ann. S. 



Afric. Mus. xx, No. 7, p. 67. 



22. xii. 25. Cape Town. From ship's sides. Two small specimens. 



Distribution. South Africa (Cape of Good Hope, Cape Town, Algoa Bay). 



Supplementary Description. Though the specimens are rather young (the largest 

 has a carino-rostral diameter of 4 mm. and aheight of 3 mm.), it was possible bystudying 

 the opercular plates to identify them as B. maxillaris. The internal parts of this species 

 have not been closely studied. As the specimens are very small and not in a good state 

 I will not give a description of the internal parts. They may best be studied in fully 

 grown specimens. 



Balanus laevis, Bruguiere, 1789. 



For synonymy see Nilsson-Cantell, 1921, Zool. Bidrag Uppsala, vii, p. 321. 



St. 52. 5. V. 26. Port William, East Falkland Island. 17 m. Gear LH. Some small and large 

 specimens on mussel shells. 



