S DR. P. P. CARPENTER ON THE SHELLS OF PANAMA. 



126. Trifon cfif)nnif;ii=.lri/(,fjiiccf/"im nofloaum, yi. 5H{). These 

 ■ilulis are siuall and tiiriettd. TIiom- i'rot. Adams inarki'd " T. viii- 

 yalaliiiii, Lain , E. Indies," are much more like the Mazatlau shtlls. 



12". Triton congfn'c(ua=Distnifio c. The specimens of this 

 irionp from the I'acitic Coast, from the Gulf of Ale.vico, aiid Irvm 

 the Cliina Seas are very dilHcult tochscriminnte. 



128. Triton fusoiiles. This unique and very elegant shell can 

 scarcely be called a Triton, even of the Epidromus type. It may 

 pcihajts rank with Eufhria, but is peculiar iu possessing a distinct 

 anterior siims, near the canal, like Rostellaria. 



129, 130, 131, 132*, 133, 134*, 135. Stent. 



I j6. Murex cluhius=iMuricidea duhia, M. 673. 



137. Murex erosHs=Muricidea e. 



13S. Murex radix = P/i)///nnotus r. The Professor's ppocimens 

 of this species are remarkal.ly fine, more nearly resemblina; the Gulf 

 tiiijritus than the heavy stumpy shells nsuallv seen. His vona^ 

 s|>ecimens are heavier, but more turreted, than the yonns: niyrttiis. 

 The opercula appear to have fewer frills ; but such differences may 

 be due only to station. The sjiecimens he marked ambiyuus (with- 

 out locality) belong to the typical 7ii(/rifus. Phijllonotus radix and 

 iiifjritii,'^ graduate into each other almost as freely as the latter does 

 into ambiguus: v. M. CGO. 



13f,. Murex rectirnsfris. This and kindred species run into each 

 other too closely, when adult, to speak with any confidence ou so 

 young a specimen in ijad condition. 



140. Murex recurvirostris. This specimen is also far too imper- 

 fect to affiliate: v. M. (j()5. 



J41. Murex regius^PhijUonotus r., M. C70. 



142. Murex salehrosus=Vitularia «., M. 612. The curious group 

 of Muricoid Purpurids culminates on the West American shores. It 

 is represented in the north temperate regions by Cerastomn, on the 

 warmer shores by Chorus, and in the tropical regions by Vitularia. 

 The Lower Californian Murex belcheri, Hds., belongs to the group. 

 Dr. Alcock (who has succeeded the late Capt. Brown as Curator of 

 the Manchester Natural History Museum) has pointed out very well- 

 marked physiologic.ll distinctions between the two fomilies, which 

 are coordinate with the differences iu the opercula. 



* Dr. Gray (Guide to MoUusca, pp. 39, 42) leaves the round-variced Ranellids, 

 as Aji'llon, in the Tritonidtp, " operc. annular, nucleus subapical, witiun the 

 apex; but removes the sharp-variced species, as Ranella, to the Ca-ssididce, and 

 figures the operculum like Bezoarrlica, " half-ovate, nucleus central, lateral, in- 

 ternal." The operculum of R. c<Hata, No. 132, is almost identical v^'ith Murex, 

 and the shell accords with Apollon; but R. nitida, No. 134, which has very sharp 

 varices, has its operculum widely removed from Bezoardica. It is closely related 

 tn that of Cerasloma, Rhizocheilun, and some of the Ocinfbrce; nucleus near the 

 anterior end of the labruin ; labral portions of the annular layers eroded ; scar as 

 iu I'urpunds, with about tliiee roughly angular ridges of growth. 



182 



