DE. T. DAVIDSOX OX EECENT BRACHIOPODA. 13 



Jeifreys is cleai'ly mistaken ; for there exists a well-marked difference LetAveen the loops 

 of T. splienoidea and T. cubensls and that of L. vitrea. The loops in the fossil speci- 

 mens of Liotlijjris spheiwklea and those of the recent X. ciibcusis are exactly the same, 

 as had been clearly illustrated by Pliilijjpi in ISii. 



As justly remarked by Prof. DaU, L. spheiioklea vai-ies much in shape according to 

 age and specimen: some are longer than wide, others almost as wide as long; some 

 taper more than otliers posteriorly, while much diflFerence is observable in the degree of 

 convexity of their valves. 



In his description of T. cuhensis, Dall enters into minute details, in order to point out 

 the differences which exist between this last-named species and Liothyris vitrea. lie 

 has also carefully studied the animal of T. cuhensis, and points out the differences it 

 presents from that of JF'aldheimia Jloridana . He says, " the mantle is of stouter consistency 

 than in IF. Jloridana, and may often be removed from the shell with but little injury if 

 care be exercised. The muscles are similar in disposition to those of the other members 

 of the Terebratulida3, and present no new features. The peduncle is solid, cup-shaped 

 at its extremity, and has the edge produced in cylindrical horny rootlets, which are 

 attached to foreign bodies. The regular arrangement in layers of the muscles and corium, 

 as well as the axial tube of the peduncle, found in Linyula, is less evident or absent in 

 these forms. In this species the peduncle is very short and stout, broadly cordiform at 

 its inner extremity when enveloped by its various tunics. 



" The brachia are arranged as in T. vitrea, as figured by Woodward ; the central coil 

 makes about four turns. The cirrhi are very short behind the mouth, in front of the supra- 

 a3S0iDhageal body. A striking feature in its anatomy, which I believe has not yet been 

 noted in any publication on Brachiopods, is the absence of that great series of sinuses in 

 the anterior part of mantle, which was termed by Hancock the ' great pallial sinuses.' 

 So extraordinary did this appear to me, that I could not believe, at first, that I was not 

 deceived by the translucency of the membranes, and it was only after an examination 

 of many specimens that I became convinced that they do not exist in this species. There 

 is in the free lobes of the mantle an extensive and extremely close and fine network of 

 minute channels ; or perhaps it might be said that the whole of the mantle-lobes form 

 one great lacune, the upper and lower walls of Avhich are held apart by a profuse number 

 of jjillars of tissue, which appear like dark spots under the microscope, and which are 

 situated so close together that the spaces about them are reduced to minute channels. 

 This system occupies the anterior lobes of the mantle, which in some species also contain 

 large branching sinuses, here absent. ... In the inner lining of the mantle are scattered, 

 everywhere, delicate, branching spicuhe, looking more like briers than like deer-horns, 

 and, while more or less interlocked, and here and there stout and thick, are still much 

 more delicate and slender than those of Terehratulina capiit-serpentis and Megerlia 

 truncata, and do not often exhibit a stellar arrangement. They are much more numerous 

 in some individuals than in others, and when present in abundance are found in almost 

 every part of the epithelium, even to the brachial cirrhi, w here the spicules are slender 

 and not branched .... The oesophagus is wide and fuunel-sha2)ed, narrowest at its 

 junction with the stomach, w'hich it enters at an acute angle. The stomach is 



