89 



versely, somewhat convex ; the anterior margin describing 

 irregularly the arc of a large circle ; the posterior margin 

 is rendered straight, thin and submembraneous, by an 

 expansion of the integuments ; the lateral margin form- 

 ing almost a right angle v.'ith the anterior edge. Eyes 

 large, and furnished with a lid which is attached to the 

 internal portion of the base of the orbit ; the eyes are placed 

 near the angle formed by the anterior and lateral margins, in 

 such a manner as to enable the animal to look above and be- 

 neath. Nostrils placed in a deep notch near the angle ; they 

 form an oblique slit, partially covered by an acutely pointed 

 process, which is continued by a loug and deep furrow along 

 the anterior margin. Mouth crescent shaped, with three 

 rows of white hyaline teeth above and below. Teeth above 

 triangular, acute, not serrated ; their tips directed outwards 

 from the centre, v/ith a shoulder on the outer side ; in the 

 centre, a few shoulders on both sides. All the branchial 

 apertures short and small ; the posterior smallest, and placed 

 over the base of the pectorals. The first dorsal quadrila- 

 teral ; second dorsal rhomboidal, very small. Pectorals low 

 down, subtriaugular, broad, distant and slightly concave be- 

 hind. Yentrals small, broad, nearly midway between the 

 first and second dorsals. Anal somewhat larger, but similar 

 in shalpe to the second dorsal. Caudal equal in length to the 

 transverse diameter of the head ; the lower lobe short, the 

 upper with a small triangular lobe near its tip. Uniform 

 dusky grey, with a very slight tinge of reddish brown ; cine- 

 reous beneath. Length, 4 to 10 feet. 



Sqnalus zijgcena, L. Syst. Nat. p. 399 ; Mitch. Trans. Lit. & 

 Phil. Soc. N. York, I, p. 284. 



Zygoena malleus, Shaw, Nat. Misc. pi. 267 ; DeKay, N. York 

 Faun. Fish. p. 362, pi. 62, fig. 204 ; Storer, Proc. *Bost. Soc. 

 Nat. Hist. I, p. 36. 



CestracLon zygccna, Gill, Ann. Lye. Nat. Hist. New York, 

 VII., p. 403. 



This pecular shark was very common last summer in the 

 mouth of Miles River, in fact so much so, as to force the 

 fishermen to abandon that ground. 



