MUSEUM OF COMPARATIVE ZOOLOGY. 19 



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(1880); depth 740 fathoms; one specimen. Lat. 33° 35' 20" N., Lon. 76 

 (1880); depth 647 fathoms; one specimen. Grenada (1878-79); depth 553 

 fathoms ; two specimens. 



Ankyroderma Agassizii, n. sp. 



What especially distinguish this form from all hitherto known ones are the 

 deposits, which form several superposed layers, so that the thin body-wall be- 

 comes rough and brittle. In the interior a continuous layer of large, smooth, 

 irregularly rounded plates is to be found ; these plates overlap each other by 

 the edges, have a smooth but uneven margin, and are perforated with numerous 

 holes, as many as sixty or seventy; the central are larger than the peripheral 

 ones. Outside of these true plates we find other deposits, which, however, 

 are not closely packed, but much scattered; they resemble the tables which are 

 found in other forms of Ankyroderma, and consist of a rather large, irregular 

 disk, perforated with a varying number of large holes and carrying a simple 

 central spine. Here and there much smaller delicate tables may be found, 

 which have a trilobate disk pierced with only three holes and resemble those 

 found in Trochostoma Blakei. Scattered among these tables are situated the 

 stellate bodies characteristic of the genus. They consist of three to six long 

 spoonlike rods, arranged with the enlarged perforated end towards a common 

 centre; the enlarged, slightly concave end is pierced with numerous holes, 

 twenty-five to thirty or more. The anchors which are connected with these 

 stellate bodies have the usual shape, their base being discoidal and perforated, 

 and their symmetrical flukes slightly serrated. 



The caudal portion of the body is strengthened by a thick layer of transverse 

 fusiform rods, with the enlarged centre pierced by a few holes. 



Otherwise, the body has the shape characteristic of the Molpodids. 



The body itself is nearly cylindrical, about 60 mm. long, wider posteriorly, 

 and decreasing slightly towards the anterior truncated end ; at the posterior 

 extremity it suddenly tapers into a narrow tail, which has a length of about 

 20 mm., so that the whole animal attains a length of about 80 mm. The 

 tentacles are drawn within the body, their true shape and number being un- 

 known. The color is light grayish inclining to violet. The radial pieces of the 

 small calcareous ring bear a bifurcate posterior prolongation. 



Another specimen was obtained at a depth of 1058 fathoms (from an un- 

 known locality), which doubtless belongs to the same species. It has 15 

 minute tentacles and some small anal papillae. 



Habitat. Bequia (1878-79) ; depth 1507 fathoms ; one specimen. 



Synapta, sp. (?). 



Habitat. Woman Key. One defective specimen, which probably is nearly 

 related to Semper's Synapta reticulata. 



