

l6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 98 



Comparisons. — This new species is allied to H. panamensis from 

 which it differs most noticeably in the characters of the interporifer- 

 ous zone of the ambulacra, which is slightly elevated with larger 

 tubercles than those seen in H. panamensis and no naked median line, 

 and in the primary spines, which are tapering and have 13-14 longi- 

 tudinal series of granules instead of being cylindrical with about 16-18 

 series of granules as in H. panamensis. 



My friend Dr. Hubert Lyman Clark, of the Museum of Compara- 

 tive Zoology at Harvard, to whom I submitted two specimens for 

 comparison with H. panamensis, writes that he regards these as young 

 specimens of panamensis, although he notes that there is some diver- 

 sity in the slenderness and form of the primary spines. He does not 

 mention the differences in the interporiferous zone of the ambulacra. 



LYTECHINUS SEMITUBERCULATUS (L. Agassiz and Desor) 



Localities. — Galapagos Islands: Elizabeth Bay, Albemarle Island; 

 south end of the black beach north of the mangroves north of the two 

 "red" islands ; July 26, 1938. Two specimens (U.S.N.M. no. E.5617). 



Galapagos Islands : South Seymour Island ; north end of the 

 plateau land section of the island ; July 29, 1938. Five dead tests 

 (U.S.N.M. no. E.5616). 



Note. — The larger of the two specimens from Albemarle Island has 

 a horizontal diameter of 28 mm. 



CAENOCENTROTUS GIBBOSUS (L. Agassiz and Desor) 



Locality. — Galapagos Islands : Elizabeth Bay, Albemarle Island ; 

 south end of the black beach north of the mangroves north of the two 

 "red" islands ; July 26, 1938. Two specimens (U.S.N.M. nos. E.5608, 

 E.5609). 



Notes. — One of the specimens is 45 mm. in horizontal diameter and 

 olive green in color. The other is 20 mm. in diameter; the test is 

 bright green with the poriferous areas abactinally light buff ; the 

 spines are dark brown becoming olive toward the base. 



ECHINOMETRA LUCUNTER (Linn6) 



Locality. — Old Providence Island, 120 miles east of the Mosquito 

 Coast (lat. i3°2i' N., long. 8i°22' W.) ; shore; reef and tide-pool 

 collecting; August 1, 1938. Four specimens (U.S.N.M. nos. E.5622, 

 E.5636). 



Note. — The largest of the four specimens measures 52 by 43 mm. 



