^gassiz.] 222 



the specimens of assimilata before me. Nor can the description ap- 

 ply to D. vicina of Hagen, since the vulvar lamina of the ? is not bifid, 

 as Rambur describes that of L. amhigua to be ; it still remains to be 

 seen, therefore, what the L. amUgua of Rambur is. 



October 18, 1865. 

 The President in the chair. 



Thirty members present. 



Mr. A. Agassiz made a communication on the development 

 of the Porcellanidse, and exhibited drawings of the zoea of 

 .Porcellana macrocheles Gibbs, from Newport Harbor, R. I. 



Dr. B. G. Wilder gave an account of a case of imperforate 

 ear in an adult. 



The possessor was a colored man named Lee Mallory, a private of 

 Co. "D." 102d U. S. Colored Troops ; 23 years old, stout of body but 

 simple and at times feeble in mind. He has never had fits, but is liable 

 to dizziness and pain in the head which is more severe behind the im- 

 perforate ear ; from this there has never been a discharge, but from 

 the left or open ear, there has been occasionally discharged a thick 

 flaky yellowish fluid. He Is quite deaf, hearing but poorly with one 

 ear and not at all with the other. 



The left ear is smaller than usual and wants the lobule, but is In 

 other respects well-formed. The right ear is as long as the left but 

 more narrow and consists only of the cartilage tightly covered by the 

 skin ; the lobule is wholly deficient ; the fossa of the helix Is not visi- 

 ble except as an oval depression where it should lie as if the helix 

 were depressed upon the fossa and had coalesced with Its floor. Tra- 

 gus very small ; antitragus present as a cartilage, but does not project. 

 Concha well defined, though small, but presents no opening whatever, 

 nor has there ever been one ; a needle was pushed to the depth of 

 half an inch through the Integument where the meatus should be, but 

 everywhere came In contact with a firm gristly substance. The upper 

 margin of the ear Is rounded as usual. 



Just In front of the tragus Is a small pedunculated papilla, about 

 two lines in diameter. It has no connection with the ear Itself, being 

 freely movable with the integument; but this man says that his father 

 and sister each have one imperforate ear, In front of which is just such 



