10 BULLETIN OF THE 



Terebratulina D'Orb. 



Terebratulina D'Orbigny, Comptes Rendus, XXV, p. 268, 1847. 

 Type T. caput-serpentis Lin. sp. Syst. Nat. Ed., XII, 1153, 1767. 



Terebratulina Cailleti Crosse. 

 Terebratulina Cailleti Crosse, Journ. de Conchyl., XIII. (3d Series, V), p. 27, 

 pi. i, figs. 1 -3, 1865. Pourtai.es, Bull. Mus. Comp. Zool., I, No. 6, p. 

 109, 1867. Dall, Am. Journ. Conch., VI, p. 106, 1870. 



This very distinct species was obtained by M. de Pourtales off Chorrera, 

 Cuba, in 270 fathoms; near Cojima, in 450 fathoms; off Double-headed- 

 Shot Key, in 471 fathoms; and near Tennessee Reef, in 115 fathoms. 

 Two specimens, from which the diagnosis of M. Crosse was drawn up, 

 were obtained at the island of Guadaloupe in two hundred fathoms, by an 

 Italian party who were searching for beds of coral. Although obtained in 

 several localities, it does not appear to be an abundant species, as the num- 

 ber of specimens obtained by the United States Coast Survey Expedition 

 was quite limited. It is well distinguished from other species by its granu- 

 lated ribs, but varies so much in form and other characters, that I doubted 

 whether all the specimens could be referred to Crosse's species, upon my 

 first examination. They all differ from his figures in a remarkable auricu- 

 lation of the valves and in the straightness of the hinge-line. These char- 

 acters, though present, vary so much in the different specimens that I have 

 come to the conclusion that the species is identical with his, and that his 

 specimens were merely an extreme variety. The normal specimens, 

 though varying in amount of inflation, almost exactly resemble Terebratu- 

 lina Miclielottina Davidson, described by that eminent palaeontologist, in 

 his monograph of the Italian Tertiary Brachiopoda (Geol. Mag., VII, No. 

 9), p. 14, September, 1870, pi. xix, figs. 22, a, b, c, from the Eocene (stage 

 E) at Mossano, Italy. Were the two found living in the same seas, no 

 one, I think, would hesitate to consider them identical. The median fiex- 

 uosity is very variable, and often entirely absent. The nodulation of the 

 ribs is more evident in young shells. They also vary from quite broad and 

 flat to elongated and much inflated. 



The smallest specimens of this species which I was able to find among 

 those sent by M. de Pourtales were nearly .1 of an inch in length. The 

 characteristic sculpture was developed upon them to the very apex of the 

 shell. The nucleus was already gone, being probably deciduous or soon 

 lost by attrition upon the rocks to which the young shells attach them- 

 selves. The various muscles were already well developed. The mouth 

 was as described in the young of the T. cubensis. The intestine was short, 

 cylindrical, and straight. The lower portion was embraced by a few 

 hepatic digitations. These lobes wei*e very dark brown, the muscles of a 



