252 J- Playfaik McMürbich, 



present. thoiigh frequently noticeable only on close iiispection. tlieir 

 distinctness being- dependent partlj^ on their coarseness and partlj 

 on the coloration, since tliey are mncli more distinct in the darker 

 varieties than in the paler ones, the difference being due to the 

 ridg-es which compose the reticulations being-, in the darker varieties, 

 either darker or paler in color than the depressions which the}' 

 enclose. 



The lobation of the margin is usnally well marked in the more 

 expanded individuals, the number of lobes varying- from flve to six, 

 though occasionally seven were observed. I have nothing to add 

 concerning the tentacles except to remark that jndging from the 

 specimens I have seen Hertwig has possibly exaggerated their 

 number in stating that they are "several thousand". The diso is 

 sniooth and Hat and the peristome usnally considerably elevated 

 above its general surface. 



The different individuals varied considerably in size, not only 

 absolutely but also in their relative proportions. One of the more 

 columnar specimens measured 2 cm in height and had a diameter 

 of about 2.3 cm, but the majority were mucli broader at the margin 

 than at the base, thus, 



A number of the specimens from Tumbes shoAved the extreme 

 flattening indicated by the lowest row of flgures. 



The coloration of the preserved specimens is very varied. Some 

 are practically colorless; other have only a narrow dark greenish 

 gray band around the margin; in others the upper half of the 

 column is of the dark color, sometimes nniformly distributed and 

 sometimes most pronounced in the depressions of the reticulation ; 

 and in others again the column is dark greenish throughout though 

 somewhat darker above than below. In other individuals, less 

 numerous in the collection, the general color is brown, varying 

 from a pale chocolate to a dark seal brown, sometimes nniformly 

 distributed and sometimes deeper upon the ridges of the reticulation. 

 In the specimen No. 69 from Coquimbo the coloration Avas almost 

 identical with that shown for A. reficulata in Dana's tab. 4, flg. 31, 



