AND SPECIES OF CRUSTACEA. 185 



SpelceopJiorus* , which it resembles in the arcuate autero-lateral 

 margins of the carapace and well-defined orbits ; but it differs iu 

 the postero-lateral margins of the carapace not being produced 

 over the bases of the ambulatory legs, in the form of the eye- 

 peduucles and anterior legs, &c. 



EXPLANATION OF PLATE XIV. 



Pig. 1. Acicsomorpka erosa (S , nat. size (outline). 



2. A dorsal view of the same animal, enlarged about four times. 



3. An inferior view, also X 4 diam., and with limbs extended. 



4. The inferior aspect of fore parts, greatly enlarged, showing eyes (a), 



inner antennae (6), and outer antennae (e). 

 6. The orbit viewed from above, showing the position of the eye-pedunclo 



(a), enlarged. 

 6. The hand, exterior view, enlarged. 



Morphology of the Mammalian Ossicula auditus. By Alban H. 

 G-. DoRAsr, F.E.C.S. (Communicated by Professor Flower, 

 F.E.S., r.L.S.) 



[Eead December 21, 1876.] 

 (Abstract.) 



The complete memoir on the small ear-bones of the Mammals will 

 hereafter be published in the Society's ' Transactions,' with copious 

 illustrations, whereby an excellent comparison of the various forms 

 peculiar to and significant of groups may be instituted. Previously 

 elsewhere t I have given a short resume respecting the material 

 which has afibrded the means of study of the series, with a brief 

 reference to what has already been published on the internal 

 auditory apparatus, and added a short notice concerning points 

 among certain of the higher groups of the Mammalia. For the 

 present abstract I shall therefore confine my remarks to the audi- 

 tory ossicles of the following orders, viz. : — the Insectivora, the 

 Chiroptera, the Cetacea, the Sirenia, the Edentata, the Marsu- 

 pialia, and the Monotremata. 



* SpelcBophorus, A!L^h. M.-Edw. Ann. Soc. Ent. France (ser. 4), v. p. 148 (1865). 

 t Proc. Eoy. Soc. vol. xxv. pp. 101-109 (1876). 

 JilNJr. JOUEN. — ZOOLOGY, TOL. XIII. 17 



