158 Miscellaneous. 



In some of the articular cartilages sometimes there are peculiarities 

 of structure which I think have never been pointed out, and are 

 worthy of notice. 



In the articular cartilage of the condyles of the os femoris, I have 

 occasionally noticed numerous minute lacunae ?, found in greatest 

 abundance near the surface of attachment, and gradually decreasing 

 in number until they entirely disappear in the superficial third of 

 the cartilage. They are elongated, compressed, and their long 

 diameter is invariably situated transversely, at right angles to the 

 filamentous matrix, or parallel with the surface of the cartilage. 

 The longest measure transversely -ysoo ^^ ^^ inch, the shortest yyVj 

 of an inch, in the vertical direction -^2^0 ^^ ^^ inch. When well- 

 defined, they appear more transparent than the cartilaginous matrix 

 in which they are situated ; when viewed a little within the focus 

 they appear deep black. 



Fibres of bone are not unfrequently met with in the articular car- 

 tilages, especially in that of the head of the os femoris. They are 

 generally found near the surface of attachment, but are not the con- 

 tinuation of the bony structure upon which the cartilage is placed, 

 for they are always arranged in a direction parallel to the surface 

 They are compressed cylindrical in form, and in transverse section 

 present an elliptical figure, the long diameter of which is placed at right 

 angles to the filaments of the cartilage matrix. They present a con- 

 centrically laminated and a radiated structure, resembling somewhat 

 that of the Haversian ossicle, but they neither present the canal nor 

 the Purkinjean corpuscles. — Proceedings of the Academy of Natural 

 Sciences of Philadelphia, vol. iv. p. 117. 



NOTICE OF AN EXCAVATING CIRBIPEDE. 



On the 8th of last June Mr. Albany Hancock communicated to a 

 Meeting of the ** Tyneside Naturalists' Field Club," an account of 

 an excavating Cirripede which he had recently discovered on the 

 neighbouring coast. This animal possesses much interest, not only on 

 account of the peculiar habit of burying itself in the shell of mollusks, 

 but likewise for its remarkable deviation of form from all the known 

 types of the class. No part of the animal, though unprovided with 

 shelly plates, is exposed, except two lips which guard a small narrow 

 opening in the surface of the substance in which the Cirripede is 

 concealed. 



On the Arrangement of the Areolar Sheath of Muscular Fasciculi and 

 its relation to the Tendon. By Dr. Leidy. 

 It is well known that the fasciculi of fibres of the muscles are 

 surrounded by sheaths of areolar tissue, but the arrangement of the 

 filaments of fibrous tissue forming the sheaths, and their relation 

 with the tendon, I think has not been properly pointed out. From 

 repeated observation, I have found that the filaments of fibrous tissue 

 cross each other diagonally around the muscular fasciculi, forming 

 a doubly spiral extensible sheath. None of the filaments run in the 

 direction of the length of the fasciculi, and but few are transverse. 

 Many of the filaments of a sheath form an interlacement in the same 

 diagonal manner with the filaments of the sheaths of neighbouring 



