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Memoir Sears Foundation for Marine Research 



or dredges in a few fathoms of water, and the empty cases cast up on the beach are 

 familiar objects. They are amber or golden yellow when first laid but are almost black 

 when found empty. The average dimensions are 55—63 mm long (exclusive of the 

 horns) by 34-45 rnm broad. *2* The transverse margin at the end bearing the longer 

 pair of horns 1^^ is straight or somewhat ragged, the margin at the end with the shorter 

 horns either weakly convex, straight, or more or less concave; the two lateral faces are 

 convex so long as the case contains its embryo. The horns taper to slender tips, and 

 they are so fragile that ordinarily only the basal parts are intact on empty cases. The 

 longer horns are nearly straight, the shorter pair more or less curved, one toward the 



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Figure 38. Raja erlnacea, egg case, from Buzzards Bay, Massachusetts, about i.iX- 



other.12^ The lateral margins are fringed with thin hair-like elastic and adhesive fibers 

 so tangled together as to form a sort of false membrane that accumulates sand or broken 

 shells and serves to anchor the case. Respiratory slits do not exist at the time the egg 

 is laid but are present before hatching (p. 142). 



In embryos nearly ready for release, the tail posterior to the second dorsal fin 

 may be as long as the disc from snout to axil of pectoral; and in some young specimens 

 the terminal prolongation may still be as long as the distance from the origin of the 

 first dorsal to the rear end of the base of the second dorsal. But in others more recently 

 hatched, as indicated by their smaller size, the tail may have shrunk nearly to its adult 

 proportions. 1" Newly hatched specimens differ noticeably from aduks in their dermal 

 armature (see p. 180). 



Habits. This Skate, like most others, is usually found on sandy or gravelly bottom, 

 less often on mud and rarely on submarine rocks or ledges. Also, it is more plentiful in 



124. Daniel Merriman and Yngve H. Olsen advise us that in Long Island Sound the median length is as small as 46 mm 

 and the median width as small as 27 mm. 



125. It is from this end that the young Skate is released. 



126. For photographs of egg cases, see Vladykov (Nat. canad., [3] 7, 1936: 213, 216) and Breder and Nichols (Copeia, 

 1937: 182). 



127. For an account of the cleavage of the egg, see Ryder (Bull. U. S. Fish Comm. [1886], 6, 18S7: 8). 



