53G MELLITA PACIFICA. 



Mellita pacifica 



! Mellita pacifica Verrill, ISC", Notes Rad., p. SIS. 



T am inclined to believe that this species will prove to he large specimens 

 of Mellita Stokesii. The only specimen of it found thus far is so much 

 largei' than any specimens of M. Stokesii that no direct comparison can he 

 instituted. The more striking points of difference are the central position 

 of the vertex, and the peculiar position of the posterior interambulacral lu- 

 nule, in front of the two posterior lunules, while it is behind in M. Stokesii. 

 This lunule is placed half-way between the edge and apex, instead of being 

 placed in the immediate vicinity of the edge, as in all specimens of M. 

 Stokesii thus far examined ; this removes the anus close to the mouth. The 

 similarity of the ainbulaeral furrows with those of M. Stokesii is quite strik- 

 ing. The closed anterior or posterior lunules also occur in M. Stokesii, as is 

 seen in specimens collected at Panama by Dr. Maack. These differences 

 are. I am aware, no greater than variations noticed in the different species 

 of Encope. In .Mellita. however, so far as known, the differences in the 

 characters mentioned above are not so great as in the species of Encope. 

 The color of the dried specimen in the museum at Yale is deep green. 

 Peru : Panama, 



Mellita sexforis 



Echinoitiscus sexiesperforatus Lebke, 177S. Ki.. Add. 

 ! Mellita sexforis A. A... 1872, Rev. Ech. Pt. I., p. Ml. 

 (See Part II p. S20.) 



PI XI. f. 1-12; * PI XF.f. 3. 

 West India Islands ; Florida. 



Mellita Stokesii 



: Encopi Stokesii Aoass , 1841, Mon. Scut. p. 59. 

 ! MelUta Stokesii A. Ac, 1872, Rev. Ech., Pt. I. p. 141. 



PI. XIII d . f. i. 



Professor Agassiz placed this species in the genus Encope from its exterior 

 appearance, although he pointed out. at the same time, the great differences 

 existing in the internal structure, which is identical with that of Mellita. 

 We find in this species no calcareous wall separating the intestine from 

 the buccal cavity, but only the calcareous network extending from the 

 edge towards the centre, having an identical structure with that of all the 



* This is quoted by mistake as XI". f. .:, p. 320, 4th line from top. 



