336 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



cirri or in any other characters. He recorded that on writing me concerning his 

 difficulties I had replied that while the species of Tropiometra are very difficult to 

 distinguish, I found "no difficulty in distinguishing" the group in which I placed picta 

 from that in which I placed carinata "by the difference in length of the outer cirrus 

 segments." On receipt of this letter he again went over the cirri, but found liimself 

 absolutely unable to detect the difference named. He said he had therefore very 

 reluctantly reached the conclusion that he could not recognize picta as a valid species, 

 but must designate his Tobagoan comatulids by the old Lamarckian name — carinata. 



In my report on the crinoids of the Siboga expedition published in 1918, I in- 

 cluded a key to the species of the genus Tropiometra. In this key T. carinata was 

 given as occurring in southern and southeastern Africa and among the islands in the 

 southwestern Indian Ocean, and T. picta was said to range from Venezuela and the 

 southern Caribbean Sea southward to southern Brazil. In the key carinata is given 

 under the heading "cirrus segments very short, more than twice as broad as long," 

 and picta under the heading "cirrus segments longer, in the outer half or two thirds of 

 the cirri much less than twice as broad as long." 



In his memoir on the littoral echinoderms of the West Indies published in 1919 

 Dr. H. L. Clark said that at Tobago he found a comatulid, Tropiometra carinata, 

 common in very shallow water in Buccoo Bay and on Buccoo reef. He remarked that 

 this is a species of wide distribution on the coasts of southern Africa and Brazil and 

 reaches its northern limit in deep wate'r (200-300 fathoms) off St. Lucia. As a littoral 

 species its northern limit seems to be at Tobago. 



In 1920 Dr. Th. Mortensen published in detail the results of his studies on the 

 early stages of Tropiometra carinata carried on at Tobago in March and April, 1916. 

 This memoir was reviewed at considerable length by Dr. F. A. Bather in 1921. 



In my memoir on the crinoids collected by the Barbados-Antigua expedition of 

 the University of Iowa published in 1921, 1 mentioned, as an Ulustration of the paucity 

 of the data regarding the crinoids from very shallow water in the western Atlantic, 

 that, except for Tropiometra picta, which is locally abundant from Tobago, Trinidad, 

 and Venezuela to southern Brazil, there are only six records. In a general account of 

 the Recent crinoids published in 1921, I quoted Dr. H. L. Clark's observations on the 

 stomach contents of Tropiometra picta at Tobago. 



In a memoir on the echinoderm fauna of South Africa published in May 1923, Dr. 

 Hubert Lyman Clark recorded two specimens of Tropiometra carinata from Mozam- 

 bique, one from Delagoa Bay, and one from off the Itongazi river. Natal, in 25 fathoms, 

 giving notes on the first mentioned. He said: 



The distribution of this species is of considerable interest. It ranges from the Seychelles, 

 Reunion, Mauritius and Zanzibar southward to the Cape of Good Hope and thence northwestward 

 to St. Helena, Brazil and the southernmost West Indies. It is true that Mr. A. H. Clark considers 

 the specimens from the latter regions specificallj' distinct from those taken on the east coast of 

 Africa, but a prolonged comparison of specimens from Tobago, B. W. I., with individuals of the same 

 size from Zanzibar has satisfied me that the supposed differences do not exist. 



In my memoir on the crinoids collected by the Ingolf published in 1923, I listed 

 two species of Tropiometra from the Atlantic. One of these, T. picta, was said to range 

 from Venezuela, Trinidad, Tobago, and St. Lucia southward to Santa Catharina 

 Island, Brazil (lat. 27°30' S.), and St. Helena, in 0-508 meters. The other, T. carinata, 



