DE. T. DAVID8()N ON EECENT BRACHIOPODA. 217 



Lingula Mans, G. B. Sowerby, Thes. Concb., Monogr. of Limjula, p. 338, pi. Ixvii. fig. 1, 18 IG; 

 Davidson, Ami. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 377, 18.")2 ; L. llccve. Conch. Icon., Mouogr. of 

 Lingula, pi. 2. fig. \2u-b, 1859; E. Suess, Ueber die Wohnsitzc dcr Bracbiopoden, Sitzungsb. k. Akad. 

 ■Wissenscli. Wien, Bd. xxxvii. p. 229, 1859; Gratiolct, l^tudes anatoniiqucs de la Lingula anatina, Journ. 

 de Concb. 2° ser. vol. iv. 18G0 ; Dall, Amcr. Journ. of Conch, vol. vi. p. 15G, 1871, and Proc. Acad. 

 Nat. Sci. Philadelphia, p. 203, 1873. 



Shell thin, lengthened oblong, rather broadest anteriorly and tapering a little 

 posteriorly ; beak of ventral valve extending considerably beyond that of the dorsal valve, 

 and much attenuated and sharply pointed at its extremity ; lateral edges of the valves 

 slightly curved inwards. Colour pale green, surface marked with numerous concentric 

 lines ; colour pale yellowish green, vivid sometimes at or near the front ; peduncle more 

 than twice the length of shell. Length of shell 1 inch 10 lines, breadth 9 lines. 



Hah. China Seas. 



Ohs. This species seems to vary a good deal in shape, some specimens being broader 

 anteriorly, others posteriorly, judging from the iigures given by Reeve. Swainson 

 says, in his paper on the species, " The belief that two distinct shells had been hitherto 

 confounded under the same name of L. anatina, first struck me when examining the 

 magnificent collection of Lord Tankerville, and the observations I have since made and 

 the numerous specimens I have examined, have both tended to strengthen this belief. 

 I have therefore here assigned to each its sj)ccific character." 



Sowerby says that L. Mans is distinguished from L. anatina " by being mucb thinner, 

 and of a more delicate green colour, it is also slightly and gradually attenuated towards 

 the base ; it only gapes at the extremities when the valves are separated from the animal 

 and dried." L. Reeve, on the contrary, states, in his monograph on Lingula, " the gaping 

 of this species does not appear to depend upon the drying of the shell ; it always dries 

 into a gaping attitude, which is not the case with other species." 



I am, however, of opinion that the drying has a great deal to do with the gajnng 

 observed in the dried specimens. The shell is very horny and thin, and when such is 

 tlie case the shell gets much out of shape when drying. Mr. W. 11. Dall considers 

 L. Antoni, Ki'ister, to be a synomyn of L. Mans. Prof. E. Suess admits L. Antoni 

 among the distinct species of the genus. Never having seen a specimen of Kiister's 

 species, I am unable to express any opinion with respect to its specific claims. It seems 

 like a variety of i. anatina. Some parts of the anatomy of this sjjccies have been 

 described and illustrated by Dr. P. Gratiolet in the ' Journal de Conchyliologie ' for 1860. 



119. LiNauLA EXUSTA, Reeve. (Plate XXVIII. figs. 20-21 a.) 



Lingula exusta, L. Reeve, Conch. Icon., Monogr. oi Lingula, pi. ii. fig. 9, 1859 ; Dall, Proc. Acad. 

 Nat. Sci. Philadelphia, p. 203, 1873. 



Shell oblong, much longer than wide, a little broader anteriorly ; sides almost sub- 

 parallel, slightly curved inwards near the middle of their length ; front line very gently 

 cu.rved, with a projecting angle in the middle. Valves convex, beaks obtusely angular, 

 surface smooth, shining, darkish coppery yellow-brown, especially towards the lateral and 



29* 



