REPORT ON THE BRACHIOPODA. 51 



being twice as long, and the individual filaments much more slender and five or six times 

 as numerous as the latter. According to Messrs Adams and Dall, Megerlia truncata occurs 

 in the Japanese seas, but I liave not seen any specimens. The habitat of the Philippine 

 Islands given by AVoodward also requires corroboration. The specimen figured lay 

 Deshayes as having l:ieen dredged off the Island of Bourbon (?) certainly belongs to 

 the species under description, but is erroneously named Morrisia gigantea. 



It is a common fossil in the upper tertiary formations of Sicily, Italy, Nice, 

 and elsewhere. 



Observations. — This is a well-known species, and has been often described, and, as may 

 be seen from the synonyms, often very much misunderstood. Externally it certainly 

 bears a somewhat obscure resemblance to some forms of Orthis, but has none of its real 

 characters. The strangest mistake, howcA'er, was that of Deshayes who described and 

 figured a specimen said to be from off the Island of Bourbon, under the designation of 

 Morrisia gigantea. In his admirable memoir Recherches sur I'Organisation du Manteau 

 chez les Brachiopodes articules, 1864, Mr E. Deslongchamps treats in minute detail of the 

 mantle in this important genus and especially of that of Megerlia truncata. He states 

 that the microscopic flattened spiculse of the mantle are still more abundant than in Tere- 

 hratulina and have a very peculiar shape, and that the calcified portions are well defined 

 in shape in both valves. The flattened spicules are wide and nearly quadrilateral with 

 rounded extremities, the edges festooned ; they form denticulated calcareous plates, and 

 vary sufficiently in arrangement in different genera of Brachiopoda as to serve as distin- 

 guishing characteristics. 



Megerlia ivillemoesi, n. sp. (PL IV. figs. 1-3). 



SheU ovate, or longitudinally oval, broadest anteriorly, tapering posteriorly. Valves 

 moderately convex, surface smooth, white. Dorsal valve moderately convex, dorsal 

 valve not quite as deep as the ventral one, and somewhat flattened anteriorly so that the 

 front line is slightly depressed. Ventral valve very convex, slightly flattened along the 

 middle and especially so anteriorly. Beak produced, comparatively large and truncated 

 by a circular foramen, separated from the hinge-line by a rather wide and high deltidium. 

 In the interior of the dorsal valve the loop is three times attached, first to the hinge- 

 plate, again to a median septum, and thirdly by perpendicular lamellae which connect 

 the lateral reflected extremities of the loop with the median septum. Length 10, -nadth 

 9, depth 5 mm. 



Habitat. — Fine examples of this interesting species attached to branched Polyzoa 

 were dredged in company with Terebratula uva by the Challenger Expedition on April 

 4, 1874, at Station 163, in lat. 36° 56' S., long. 150° 30' E., off Twofold Bay, South 

 Australia, or between Sydney and Melbourne, in 120 fathoms. Bottom temperature, 0°7 C. 

 Sea bottom, red clay. 



