Hab. ad oras Brasiliae. 



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



SiPHONARiA L^viuscuLA. Sipk. testd subdepresso-comcd, sub' 

 obliqud, extiis pallidd, radiatim albido-lineatd ; inids fuscescente ; 

 margine albicante : long. 0"9, lat. 0'75 poll. 



Hab. ad Ydparaiso. 



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



SiPHONARiA MAURA. SipJi. testd purvd, dcpressd, subovali, intHs 

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

 diatd : long. 05.5, lat. 045 poll. 



Hab. ad Panamam. 



Found on rocks. — G. B. S. 



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

 syurus, Dasyurus macrourus, Geoff., which recently died at the So- 

 ciety's Gardens. 



The subject was a female, adult, weighing 3lbs. 84- oz., and mea- 

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

 4 inches, the length of the tail being I foot 24- inches, and that of 

 the head 4 inches. The vaginal 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 quarters 

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

 sponding shape, 3 inches anterior to the cloacal outlet. 



The external oblique abdominal muscle terminated below in a 

 strong tendon, which was folded inwards, like Poupart's ligament. 

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

 part's ligament, and internally by the marsupial bone: and Mr. 

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

 tially ossifications of the tendons of the external abdominal muscle 

 which constitute the internal or mesial pillars or boundaries of the 

 abdominal rings. The transversalis abdominis and internal oblique 

 muscle were distinct. 



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

 greatest circumference. It was shaped as in the genus Didelphis, 

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

 tremity. It was principally 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- 

 minal part of the (esophagus was furnished with longitudinal rug<e. 

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

 was occupied by a zone of glands. 



The omentum 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<Eum, 

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



