DKsoK'irrioN's ok nkw sdiriii \vAr,Ks fossils KTIIKKHKIK. 189 



tletlected backwards as in an ordinary pleurotomai'id baud ; the test is not 

 preserved on the lower or flattened surface. 



The presence of this periplieral band at once removes tlie species from 

 the genus Pl((fij>«'lil!<iit((, and indicates Keeiicia, mihi, as a suitable i-esting 

 place, thus introducing adepi-essed foi-m into an otherwise trochifoiTii genus. 

 Now, in P. (icnhd!, although the growth sculpture passes over the obtuse 

 periphei"al keel, there is no ti'uncate periphery bearing a band. 



Platiji^chis))t(i rot III! ddt It 1)1, var. fdrlei/ensis, var. uov. (PI. xxviii., fig. 

 9). — Associated in numbers with the liraonitic Martin! opsis, Plearopliorus 

 gre(j(tn'ug, and Stntchbnria farleijensin casts at Farley, are similar kernels of 

 small l'l((tijxc}iis))i<i rotiimlatiiDh. All I have seen are of a common size, less 

 than the normal dimensions of examples of the species obtained elsewhere. 

 On these internal casts, the sulci resulting from the protrusion of the 

 inner shelly ribs, described by Morris, are always in evidence and well 

 displayed. The casts seldom exceed one and three quarter inches in 

 gi-eatest basal diameter, and three quarters of an inch in height, they 

 appeal to me as a stunted growth of the ordinarj^ P. rotaudatum. 



V. — Various Species described by Dana. 



Amongst the Pelecypoda collected in New South Wales by Prof. 

 J. D. Dana were two species described as Gardinia (?) rectiO-^ and C. (0 

 citneata,^'^ and as Solecnrtus two species, S. (?) ellipticns^^ and (S. (Psam- 

 mohia?) plantdatus.^^ To Gypricardia were also referred G. aciUifrons,^^ G. 

 imbricafa,^^ G. arcodes,^^ G. prreriq)ta,^'^ G. siiiijjlex,''^* G. (Avicul-x ?) venerii^,'^^ 

 and G. siliqua.^^ Of the above I have already dealt with Gardiula simplex, 

 referring it to a new genus, Statchhuria. 



The following remarks on ten of the above are based on replicas of 

 Dana's types. These were most obligingly supplied by the United States 

 National Museum, Washington, where Dana's gatherings are located. 



1. \_Gardinia'\ recta, Dana. — When describing StntrJihariu fnrlt'i/ensis 

 I alluded to Gardinia (!) recta, and (,'. (?) cnneata as possibly referable to 

 Stutchhnria, " in which case the generic characters of the latter, will of 

 necessity require to be slightly modified" to allow of the inclusion of more or 

 less similar bivalves, but with nasute posterior ends. This suggestion will 

 stand good with regard to G. (?) recta, but not I now believe in the case 

 of C (?) caneata. By incorporating the first of these bivalves in Stutch- 

 hnria it will not be necessaiy to enlarge the generic characters in question. 

 I have before me a cast of one of Dana's types of his G. (?) recta''' (PI. 



i« Dana— Wilkes U.S. Explor. Expedn.,x. (Geology), 1849, pi. iv.,figs. 5, 5a and b. 



'" ,, ,, ,, pi. iv., figs. 6, 6a-(L 



"* ,. ,, ,, pi. ii., fig. 9. 



''■• ,, ,, ,, pi. ii., fig. 10. 



-" ,, ,, ,, pi. viii., figs. 4a and 6. 



"' ,, ,, ,, pi- viii., fig. 5. 



-^ ,, ,, ,, pi. viii., fig. 8b. 



"' >> ). ,, pi- viii., fig. 10. 



■-•' » ., „ pi. ix., fig. 2. 



-' ,, ,, ,, pi. ix., figs. 3a and h. 



-* ,, ,, ,, pi. ix., figs, la and h. 



^' ,, ,, ,, pi. iv., fig. 5. 



