110 DE. T. DAVIDSON ON EECENT BEACHIOPODA. 



G. B. Sowerby to liaAe been found by Mv. Cuming attached to corals at Calapan, Isle of 

 Mindoro, also off the Island of Cocos (Lieut. Swainson). The shell has been dredged 

 by Mr. J. Brazier oif the Bottle and Glass rocks, Port Jackson, Australia, and at other 

 places in the same region. (PL XX. figs. 9-11.) 



Obs. Mr. E. Donovan, in vol. ii. (1824), of his ' Naturalist's Ptepository,' tells us that 

 *' this elegant little testaceous body is eminently entitled to the consideration of the 

 naturalist, being no other than the true Anomia Criienta of Dr. Solander's manuscripts, 

 preserved in the Banksian library, and of the Portland Museum to which the Solandrian 

 manuscripts refer ; it is consequently the shell which has been so uniformly mistaken for 

 and confounded with the Anomia sangiiiuea of the same author, and not unfrequently 

 with his Anomia rvhicunda also." Such may perhaps be the case ; but as Solander did 

 not publish a description of his shell, Ave are bound to take the name of the Anomia 

 sangitinea described and figured by Chemnitz in 1785. To a bleached specimen from 

 Japan, A. Adams, in 1863, gave the name of Ismenia JReevei (PI. XX. figs. 12, 12 b of this 

 work), and Mr. L. Eeeve states, in his description of T. sanguinea, that " An examination 

 of more than a dozen specimens of this charming species, most of them with the soft 

 parts macerated, so as to afford excellent comparisons of the loops, has convinced me 

 that Mr. Sowerby's T. ^yvlcheUa {Megerlia irnlcheUa, Davidson) is merely a variety of the 

 old Anomia sanguinea of Chemnitz." If only Sowerby's figures of T. sanguinea and T.pul- 

 chella are compared, one might perhaps feel disposed to conclude that they represented 

 different species ; but when one examines, as I have done, a large number of individuals, 

 it is soon found otxt that the two extreme forms are connected by intermediate or passage 

 ones. The red spots on the shell also vary much in extent, and even shaj)e, sometimes 

 forming a longitudinal and rather wide mesial band with a small yellow band on each side, 

 on Avhich none are visible, and in some examples short ribs are also observable near the 

 margin in both valves. 



M. E. Deslongchamps, in his paper already referred to (p. 102), classes T. sanguinea with 

 Terebratella, and describes some of the changes it undergoes from the youngest stage up 

 to the adult condition. He says " that the brachial apparatus or loop is more comj)licated 

 than that of true Terehratellce , and very similar to what we observe in the IlegerJiforni 

 stage of Waldheimia septigera, but with an additional complication." In my opinion 

 T. sanguinea is not a true Terebratella, and, if not a Megerlia, would require to be left 

 with Ismenia or some other genus. In plate xvii. of the work just quoted, Deslongchamps 

 figures the passages of T. sanguinea from the Platydiform into the Magadiform stage at 

 the dimensions of 4 millimetres, the commencement of the Megerllform stage at 8 

 millimetres, and the Megerliform stage of the species at the dimensions of 10 millimetres 

 (see our PI. XX. figs. 4, 5, 6, 7, 8 ; and the corresponding explanations). 



Mr. Ball, in his paper in the Amer. Journ. of Conch, vol. vi. p. 128, 1870, when 

 describing Ismenia sanguinea, mentions that "There is some variation in tlie obliquity 

 and breadth of the apophyses in different individuals, but the essential characters remain 

 the same. The punctures in the shell are larger and more conspicuous than in any 

 species of the group with which I am acquainted. The imbricating prisms of which the 

 shelly structure is composed are beautifully conspicuous with a very low power, inside; 

 and even the apojohyses seem to exhibit the same or a similar structure, though impunc- 



