Hab. ad oras Brasilise. 



Found on rocks in expo3ed situations. — G. B. S. 



SiPHo.VARiA L^viuscuLA. Stph. testč. subdepresso-coūtcd, sub- 

 obligud, eitiis pallidd, radiatim albido-lineatd ; intils fuscescente ; 

 margine albicante : long. 09, lat. O' 75 poli. 



Hab. ad Valparaiso. 



On rocks iii sheltered places. — G. B. S. 



SiPHONARiA MAURA. Siph. tcstd purvd, depressd, subovali, intils 

 nigrd, margine albido articulato ; eitiis fuscescente, albido-ra- 

 diatd : long. 055, lat. 045 poli. 



Hab. ad Panamam. 



Found on rocks. — G. B. S. 



Mr. Owen read some Notės of a Dissection of a long-tailed Da- 

 syurus, Dasyurus macrourvs, GeofF., which recently died at the So- 

 ciety's Gardens. 



The subject was a female, adult, weighing 3lbs. 8^ oz., and mea- 

 suring from the extvemity of the jaws to the root of the tail 1 foot 

 4 inches, the length of the tail being 1 foot 2-į- inches, and that of 

 the head 4 inches. The vaginai orifice and the anus were situated 

 within a common outlet, just below the root of the tail. There were 

 six nipples, arranged three on either side, describing three ąuarters 

 of a circle, and seated within a slight fold of integument, of a corre- 

 sponding shape, 3 inches anterior to the cloacal outlet. 



The extemal obliąue abdominal musele terminated below in a 

 strong tendon, which W£is folded inwards, likę Poupart's ligament. 

 The abdominal ring consisted of a slit, bounded extemally by Pou- 

 part's ligament, and intemally by the msirsupial bone: and Mr. 

 Owen stated it to be his opinion that the marsupial bones are essen- 

 tially ossifications of the tendons of the extemal abdominsd musele 

 which constitute the intemal or mesial pillars or boundaries of the 

 abdominal rings. The transversalis abdominis and intemal obliąue 

 musele were distinet. 



The stomach was simple, 4-i- inches in length and 8 inches in its 

 greatest circumference. It \ras shaped as in the genus Didelphis, 

 and had the cardia a little nearer to the pyloms than to the left ex- 

 tremity. It was principaUy nourished by the coronary arteries ; the 

 gastro-epiploics being very small and running along the posterior 

 side of the stomach, and not along the greater curvature. The ter- 

 minai part of the asophagus was fumished -nith longitudinal rug<e. 

 The commencement of the duodenum, to the extent of half an inch, 

 was occupied by a zone of glands. 



The omentvm was of small size, extending from the stomach to 

 the spleen, but not covering the intestines : it is possible that as 

 these are short and wide, they do not require such a covering to fa- 

 cilitate their motion. It contained a little fat. 



The mesentery was one continuous duplicature of the per iton<emn, 

 estending from the pylorus to the end of the colon, as in the Rep- 



