23 



Venus spurca. Ven. tesld ovatd, crassd, sordide fulvd fusco ra- 

 diatim 7naculosd, concentrice subobsolete costellatd, costettis obtu- 

 sis,prope latera subinterruptis ; margine ventrali inttis denticulato: 

 long. 1-1, lat. 0-6, alt. 0-9 poll. 

 Hab. ad Valparaiso. 



Found in coarse sand at a depth of from thirty to fifty fathoms. 

 — G. B. S. 



Genus Cytherea. 



Cytherea radiata. Cyth. testa, subtrigond, subcequilaterd, gibbosd, 

 pallescente brunneo radiatd et undulatim pictd, lavi, epidermide 

 corned crassiusculd plus minusve indutd ; lateribus antico postico- 

 que ventrem versus rotundatis ; margine venti-ali rectiusculo, inttis 

 lavi : long. 2*5, lat. \b, alt. 2" poll. 



Hab. ad oras Columbise Occidentalis. (Salango and Xipixapi.) — 

 G. B. S. 



This species belongs to that division of the genus which has four 

 cardinal teeth, and is destitute of the cordiform anterior impression. 



Found in sandy mud at a depth of nine fathoms. — G. B. S. 



Cytherea unicolor. Cijth. testd ovato-subcordiformi, crassius- 

 culd, brunnescente, lavi, politd ; lateribus antico posticoque con- 

 centrice sulcatis, sulcis medio obsoletis ; latere postico longiore, 

 versus partem ventralem subacuminato ; margine ventrali Itevi, 

 intits purpurascente : long. \'6, lat. 0'75, alt. 1'3 poll. 



Hab. ad Real Llejos Americae Centralis. 



Variat testd majore, albicante. 



Found in coarse sand at a depth of six fathoms. — G. B. S. 



Cytherea concinna. Cyth. testd ovato-subcordatd, crassiusculd, 

 rubente albicante radiatd ; latere postico longiore, subacuminato ; 

 costellis numerosis, concentricis, obtusis, concinnis, confertis : 

 long. 1'6, lat. 0'8, alt. 1'2 poll. 



Hab. ad Panamam. 



Found at a depth of ten fathoms in fine sand. — G. B. S. 



Cytherea squaliua. Cyth. testd ovato-subcordatd, crassiusculd, 

 leevi, pallide fused , nonnunquam maculis irregularibus saturatiori- 

 bus ; epidermide fused ; latere postico longiore, prope partem ven- 

 tralem subacuminato : long. 2'7, lat. 1"3, alt. 2* poll. 

 Hab. ad Sanctam Elenam. 



This shell bears some resemblance to Cyth. maculosa. It has ge- 

 nerally a very dull and dirty aspect. One of the several varieties in 

 Mr. Cuming's collection is rather agreeably ornamented with con- 

 centric purple bands. 



Found in sandy mud at a depth of six fathoms. — G. B. S. 



A paper was read by Mr. Owen, entitled, " Description of a Micro- 

 scopic Entozoon infesting the Muscles of the Human Body." The 

 author observes, that upwards of fifteen different kinds of internal 

 parasites are already known to infest the human body, but none have 

 been found of so minute a size, or existing in such astonishing num- 



