68 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I49 



Plate 15. SIX SPECIES OF FLORIDA ECHINOIDS 



1. Echinonens cyclostomus Leske. Station 60; USNM E10318. Adapical view 



of specimen photographed in alcohol (X2). 

 2-3. Plagiobrissus grattdis (Gmelin). Station 30. 



2. Adapical view of immature specimen (35 mm. long) for comparison 

 with adult in figure 3 (X 1.5) ; USNM E 10304. 



3. Adapical view of adult (140 mm. long), X2.8; USNM E10305. 

 4-5. Brissus unicolor (Leske). 



4. Adapical view of specimen photographed in alcohol (X 2) ; station 

 60; USNM E10317. 



5. Adapical view of denuded test (X 1.5) ; station 17a; USNM E10316. 



6. Mcotna ventricosa (Lamarck). Station 23. Pedicellaria clasping an ostracod 



(X30). 



7. Encope michclini Agassiz. Station 45 ; USNM E10308. Tetramerous variant 



lacking ambulacrum IV and its associated half-interambulacra (X 1)- 



8. Clypeaster subdeprcssus (Gray). Station 61; USNM E10307. Adoral view 



of specimen presumably attacked by a fish as evidenced by the teeth marks 

 on the test. (XH). 



Plate 16. ABNORMAL ECHINOIDS— TETRAMEROUS VARIANTS 



1-4. Echinomelra lucuntcr (Linnaeus). Molasses Key; USNM E10306. 



1. Adoral view showing five ambulacra, five interambulacra, but with 

 ambulacrum I and its half-interambulacra terminating a short distance from 

 peristome (X 1^)- 



2. Adapical view showing only four ambulacra and interambulacra (X 

 I/2). 



3. Apical system showing absence of pores in posterior genital plates, 

 presence of two probable genital pores in ocular I (X 5). 



4. Enlarged view showing total extent of ambulacrum I (X 5). 

 5-6. M coma ventricosa (Lamarck). Station 23 ; USNM E10311. 



5. Adapical view showing onlv three petals, the left anterior petal absent 

 (X 0.6). 



6. Adoral view showing absence of phyllode IV (X 0.6). 



