1873.] 131 [Putnam. 



and one half times in the abdominal portion (the portion embraced 

 between the branchial apertures and the anus). The tail (meas- 

 ured from the anus to the tip) is one eighth of the total length. 

 The lingual teeth are the same on each side, the outer row being 

 composed of the largest teeth, as is the case with all known speci- 

 mens of the genus. There are nine in the outer, and ten in the 

 inner row. The two foremost of each row are the strongest, and are 

 confluent at the base. 1 The dorsal fin commences a little more than 

 the length of the tail in advance of a point over the anus. This 

 specimen is not fully developed, but with the aid of a lens, minute 

 eggs can be seen in the ovary. 



On examining three specimens contained in the Museum of the 

 Peabody Academy of Science, and collected by Mr. Mills at Grand 

 Menan, during the season of 1857, I found one that was much more 

 slender than the others, agreeing very closely in its proportions 

 and the length of the dorsal fin, with the specimen described above. 

 This is a fully developed female, with large eggs. It measures fifteen 

 and one half inches in total length, and .6 of an inch in depth. The 

 head is one quarter the total length, and is contained two and 

 and one half times in the length of the abdomen. The lingual teeth 

 vary in number on the two sides ; the right side having eight in the 

 outer row, and eleven in the inner ; the left side has nine in the outer, 

 and ten in the inner row. 



The other two specimens from Grand Menan are at once notice- 

 able from their more contracted form. They agree in their relative 

 proportions, and in having a short dorsal fin, which commences but 

 little in advance of a point over the anus. One of these is a fully 

 developed female, with large eggs. It is fourteen inches in length, 

 and .7 of an inch in depth. The head is contained three and one 

 half times in the total length, and twice in the length of the abdo- 

 men. The tail is contained seven and three quarter times in the 

 total length. The lingual teeth are ten in each row. 



The third specimen is a female, with the eggs but little developed. 

 It is 12.9 inches long, and .6 of an inch in depth. The head is con- 

 tained three and one half times in the total length, and twice in the 

 length of the abdomen. The tail is contained seven and one half 

 times in the total length. The lingual teeth are nine in each row. 



1 A character which is common to all the specimens of the genus I have exam- 

 ined, though it has been stated that in M. australis the first three teeth are con- 

 fluent. 



