I naV( in naming this fine and characteristic deep-sea species after the 



tpedition, Profcj Max Weber. 1i was taken at .1 depth of 560 m., 



and thu 'ered a d< species. 



I( it shows a certain resemblance to />. orthogonia and belongs 



: • nus, luit it differs (rom it by its size, as well as by the shape 



and of the disc forming the base of the carina. 



:n species and />. sesst/ts Hoek, dredged l>\ the " Challenger" in the Atlanl 

 . .it a depth ui fathoms, are the only known species ol the genus Dichelaspis 



livinj depths. 



ispis Versluysi n. sp. PI. 111, fig. 8 — [3. 



ipitulum compressed, apex produced. Scuta with the basal segment much narrower 

 than the occludent segment and more than half as long. Terga with three distinct marginal 



•:is and a fourth one very small. Carina terminating downwards in an oval disc-like cup. 



Genera] appearance. Capitulum llat: valves small, a large part of the surface of 

 the capitulum remaining uncovered. Valves covered by membrane so as not t" beseen distinctly 

 without isolating them. Peduncle cylindrical not quite half the length of the capitulum (PI. III. fig. 8). 



S ntuni (fig. o*?'. It consists of two bars placed in most oi' the specimens at right 

 angles to each other, in one of the specimens (figurcd in fig. 9) at an angle of more than 90 . 

 The point of junction is perfectly calcified. The basal segment uniformly narrow, the occludent 

 segment, which is less than twice as long as the basal segment, grows much wider towards 

 the apex. It is flat with the apex obliquely truncated. 



1 ergum (fig. tjó) of a triangular shape, with three ridges terminating in three 

 prominences of unequal length. Seen from the outer side the three divisions are separated from 

 one another by distinct. even deep furrows. The fourth ridge or prominence is extremely small 

 and situated at the carinal side just above the apex of the carina. 



1 tri na (fig. <i ( - . Much bowed, even slightly more than is the case in D. W'c/'cri. 

 long. not very narrow, keel-shaped in its basal part and with a flattened central ridge above 

 the middle to as far as the apex. Internally the valve is concave. The basal portion is embed 

 and forms a cup of a verj peculiar shape: it is oval with at each side a small wing, like the 

 small handles of a bowl PI. II, fig. 10a, while fig. 10/; shows the cup-shaped basal portion 

 of a specimen of D, orthogonia with the same enlargement, seen from the same side). 



Peduncle short, cylindrical-, length about one third that of the capitulum. In most of the 

 ■neus the chitinous outer wall is transparent and surrounds the muscular part like a wide sack. 



Size. Length of the capitulum in one of the larger specimens 6,3 mm. when measured 

 from the tip of the tergum to the base of the carina. Several specimens, however, are considerably 

 I';. largest specimen is over ~ mm. 



The mouth and its parts in genera! resemble greatly the same paris in /). orthogonia: 

 labrum with a row of small bead-like teeth; palpi with the two sides parallel, 

 • one side numerous very long bristles. 



