but the cluster is much more slender in proportion to their 

 length and the arrangement of the capsules is less regular. 

 "The species is known only from Greenland and the Polar Sea." 



That the egg-clusters obtained by Mr. Fuller were those 

 of C. decemcostatus was readily proven by finding among some 

 egg-capsules of B. undatum in the collection of the Society a 

 small cluster of the former, about one inch in height, from which 

 I took embryonic shells of C. decemcostatus about 7 mm. in 

 length ; the smooth protoconch of about two whorls was followed 

 by half a whorl, having about nine revolving ridges, the anterior 

 ones poorly defined. 



The three cylindrical clusters of egg-capsules were obtained 

 from a depth of about 45 fathoms between the Georges and 

 Nantucket Shoals, attached to living specimens of the Great 

 or Deep-water Scallop {Pecten magellanicus Gmelin). Two 

 were attached to one shell about 1.25 inches apart, as shown 

 in the photograph (Plate 1, fig. 2). The length of the clusters 

 varies from 3 to 3.5 inches (75 to 90 mm.) with a diameter at 

 the base of about 1.5 inches (37 mm.) and at the top 1.25 inches 

 (31 mm.). For a better anchorage the attached portion of the 

 base extends on all sides about a quarter of an inch beyond 

 the capsules. There are between 45 and 50 capsules in each 

 cluster, which, when taken from the water, were lemon yellow 

 in color. Each capsule is about half an inch in diameter, convex 

 above and roughened by reticulated lines. As the specimen 

 dries, these lines become more pronounced by the contraction 

 of the interstices, giving the surface a pitted appearance. The 

 attached portion of each capsule is broad, contracted above and 

 then expanded into the broad capsule, which is folded down 

 on the one below; the base of the upper one is usually attached 

 to the upper sides of the two below, thus overlapping like the 

 tiles on a roof and arranged somewhat spirally, the contracted 

 portion serving as a hinge, beneath which are openings through 

 which water can flow and the young escape. As the opening 

 of the capsule is a wide slit at the end just under the top, this 

 portion of the capsule is always free. 



There were apparently from three to four eggs in the fresh 

 capsules, but in the old dry capsules there were only one or 

 two young shells. In this connection it might be of interest 

 again to refer to the following paragraph in Dr. Dall's paper. 

 **In many cases, as in Buccinum and Busycon, it was shown 

 many years ago by Lov^n and others that a single ovicapsule 



