U Y C E T P U S . 



SpecifS 9. (Fig-, a, h, ;^[l\s. So\verl)y.) 



r.ini'Ls IWLCATUS. Mijc. Inld epkltnnuh driata, 

 <t!,caci'o-fi(srd iiidiUu, eloiifjatmimd, cunealo-solmii- 

 Ifirmi, h'liui; latere postico dongaio, oMiqne aniju- 

 lafo, siibfxpaiiso, ad terminum oblitjiw Irnncnto, mnr- 

 i/iiie dorsali recto, ventrali Icviler conlraclo, uwdiu 

 inigusfato, margine ventrali sinuato, Manti ; latere 

 initico in rostrum falcatum acuminatum prndncto, 

 mnrgiue dorsali prope umbones excavnto, turn itsqtie 

 ad termitmm declivi. 



HOOKED Mycetophs. SIr'H covered with n stri.-ited, 

 i>live-l)i'owii epidermis, very long, ciineate-soleniform, 

 tliin; posterior side elongated, obliquely angidar, 

 -ubexpanded, obliquely truncated at tlie end, dorsal 

 margin straight, ventral slightly contracted, middle 

 narrow, with ventral margin sinuated, gaping ; an- 

 terior side produced into a hooked, acuminated beak, 

 dorsal margin excavated near tlic ninbnes, then 

 sloped to the end. 

 (iiNS, Pro. Zool. Soc. June. ISfiS. 

 , Kiver Amazon. 



(jiiiatiix, Lea, but it is 

 acuminated, and curved 



produced. 



Several specimens of this very interesting shell having 

 come to hand, it would have been undesirable to omit it, 

 altliough we had considered the monograph made up. It 

 i- a second example of the form represented by M. emar- 



Species iU. (Mus. Sowerby.) 

 MvcETOPUs siMisiNUATUs. Mijc. testd injlald, ventri- 

 cusd, leiiiii, epidermide olivaced lavissimd iiidntd ; la- 

 tere postico lain, obliqui rotundatim anrjulato, mar- 

 gine dorsali redo, ad tfrndnum oblique subtrniicnto, 

 margiiie ventrali conve.ro, medio snbcontracto, subde- 

 presso, pauluhim siiiiialu, hianti ; latere antirii brevi, 

 angusto, rotiindato, hiunti. 

 TuE SUBSINUATED Mycetopus. Shell inflated, ventri- 

 cose, thin, covered with an olive, smooth epidermis : 

 posterior side wide, obliquely roundly angular, with 

 dorsal margin straight, obliquely subtruncated at the 

 end, ventral margin convex, middle subcontracted, 

 subdepressed, slightly sinuous, gaping ; anterior 

 side short, narrow, rounded, gaping. 

 Sowerby. 

 Hah. Bogota, New Granada. 



Among the various degrees of squareness, angularity, 

 narrowness, and ventricosity found in specimens of 2Iy- 

 cetopus siliquoides, I have met with none resembling 

 this species, in the peculiar ventral sinuous contraction 

 of tiie anterior side. 



