624 SCIENTIFIC RECORD FOR 1884. 



tion to the number of myocommas as an excellent taxonomio character.'* 

 Dr. Giinther was thus led to recojiuize six species of Br anchio stoma: 

 (1) B. elovf/atnm, Peru; (2) B. hassanum, Bass Straits; (3) B. Belcheri, 

 Borneo; (4) B. caribccum, West Indies; (5) B. lanceolattan, Europe; (6) 

 B, [Epifjonichthys] culfelhis. The B. hussanum was ne^Y. [Rep. Zool. Coll. 

 Alert, pp. 31-33.) 



Selachians. 



An Eel-UTce Shark. — Perhaps the most interesting discovery of the past 

 year among new vertebrate forms is a species of shark made known by 

 Mr. Samuel CTaruian,of Cambridge, uuder the name of GhlamydoHelachus 

 anguinens. All the i)reviously known sharks are pretty uniform in hav- 

 ing the body of a more or less fusiform contour and comparatively stout; 

 any differences in contraction or elongation are comparatively slight. 

 The new form, however, differs widely' from all other described species, 

 and is so elongated as to suggest the snake- or eel-like form, which has 

 struck Mr. Garnmn and induced him to give to it the name anguineus or 

 snake-like. In other respects, it has more characteristics in common 

 with the Notidanids or Hexanchids (that is, the family represented by 

 the gray shark of Europe) than with any other. As in the Notidanids, 

 there is only one dorsal flu, and in the new shark this is reduced in size 

 and far behind, oi)i)osite the anal; the latter is much larger than the 

 dorsal and is elongated ; the ventral tins are also behind the middle of the 

 length and reach to the anal. "The head is broad, slightly couvex on 

 the crown, and has a look about it," says Mr. Garmau, "that reminds 

 one of some of the venomous snakes." The mouth opens at the ante- 

 rior extremity, and is not overhung by the snout, as iu most sharks. 

 The gape is very wide, lateral, and extends far behind the eyes. The 

 nostrils are also unlike those of ordinary sharks in being lateral. As 

 in the Notidani<ls, the branchial apertures are in increased number (six), 

 but those iu front are very wiile, and are quite characteristic in that 

 "the frill or flap covering the first opening is free across the isthmus, 

 as in [some] fishes, and hangs down about an inch." The teeth are also 

 very peculiar. As in other sharks, they are arranged in rows acioss 

 the jaws. In detail, "they are all alike; each tooth has three slender, 

 curved, inward-directed cusps, and a broad base, which extends back 

 in a pair of points under the next tooth, thereby securing firmness and 

 preventing reversion. In the twenty-eight rows of the upper jaws and 

 twenty-seven of the lower there are three times as many rows of the 

 fangs or cusps." 



Mr. Garman, in considering the relations of this remarkable animal, 

 thought that most resemblance was to be found in the dentition to the 

 teeth of Cladodufi, of the Devonian, "but the cusps were erect iustead 

 of reclining, and the enamel wa-s grooved or plicate instead of smooth." 

 He was impressed by a study of the aniuial "with the idea that, away 

 back in time« wheu selachia ami fishes were more alike, he would 



