273 
already somewhat obscured by the first layer of carbonate of lime, 
although also here a basal margin is clearly seen. But now the 
plate develops a „spur“ from the carinal margin and downwards 
along the carina at the side of the peduncle; also now the original 
basal margin is indicated by a notch. The latter is during the fol- 
lowing apposition of calcareous substance soon filled up, and the 
occludent margin secondarily prolonged to meet the carinal margin 
directly at the side of the peduncle. Thus the scutum attains its 
triangular shape with its aberrant, long, occludent margin, and loses 
its basal margin. 
At the same time the incipient ridges are already observed, 
especially the median ridge towards the juncture of carina and 
tergum, as a radial, prominent stripe. A little later the lower crista 
of the scutum, and the carinal crista also appear. The lower crista 
of the scutum rather often may be somewhat feebly developed even 
in adult specimens which are therefore on external examination 
sometimes only with difficulty distinguished from the following 
species. 
Megalasma minus Annandale. 
Syn.: Megalasma bellum Pilsbry 1907. 
„ Megalasma lineatum Hoek 1907. 
7 miles S. of Olutanga, about 300 fathoms 8/III 14. Four specimens on 
the spine of a sea urchin. 
7° 25’ N., 123° 14’ E.; 250 fathoms. 9 /111 14. Two specimens on spines 
of a sea urchin. 
Menado Bay, 1° 31’ N., 124° 47’ E.; 250 fathoms. Captain Christiansen 
12/III 13. Three specimens on the cirri of a crinoid, together 
with Scalpellum balanoides. 
There is some variation in the species regarding the basal part 
(Fig. 30a, c); in some specimens the basal margin of the carina 
forms a direct continuation of the feebly arched occludent margin 
of the scuta, in other specimens the basal margin of the carina is 
almost perpendicular to the occludent margin of the scuta. In the 
latter case the lower part of the occludent scutal margin may be 
bowed so as to form an incipient basal margin. The specimens 
thus link the preceding species to the subgenus Glyptelasma of 
Pilsbry (1907), and the present species indeed so to say stands 
Vidensk. Medd. fra Dansk naturh. Foren. Bd. 73. 18 
