Dr. J. Young on the Malacostraca of Aristotle. 255 



object of his studies was the explanation of the phenomena of life. 

 We now know that accurate anatomy is the only sure basis of 

 physiology : but the speculations of that age followed an inverted 

 order. Descending, as Aristotle traces thought, from universals 

 to particulars, the order of ideas was supposed to represent the 

 order of events. A Final Cause was assumed as the starting- 

 point; the facts were viewed as its manifestations. How that 

 operated in multiplying difficulties I have pointed out. Its 

 cramping influence was rebelled against by Aristotle : — " It is 

 true that nature sometimes uses excretions to some good end ; 

 but we must not therefore seek a final cause in all things, but, 

 inasmuch as certain things have certain properties, there will 

 necessarily arise from these many effects." (De Part. iv. 2, 

 quoted by Lewes, p. 318.) 



The identification of the animals from which the foregoing 

 anatomical details were drawn has, of course, been frequently 

 attempted. Belief in the infallibility of Aristotle led to many 

 arbitrary interpretations, which it might be interesting, but 

 would assuredly be unprofitable, to restate. The essay by Cuvier, 

 " Sur les Ecrevisses connues aux Anciens " (Mem. du Mus. 

 t. ii.) and the chapter in Meyer's 'Arist. Thierkunde' on the 

 Crustacea are the most recent dissertations on the subject with 

 which I am acquainted. There is not in English, so far as I 

 am aware, any special treatise on the Malacostraca. 



The yevrj fMeyicrra of the group have been already mentioned. 

 The <yiv7) or elSrj included under them are — 



Astacus. 2. Fluviatile A. 

 Carabus. 



Caris. 1. k. fcvcprj. 2. /cpdy<ya>v. 3. to fiiicpbv yevos. 

 Carcinus. 1. Maia. 2. Paguri. 3. Heracleotici. 4. River 

 Carcini. 5. Small forms, unnamed. 



Astacus. — The description of this form (H. An. iv. 2. 6) leaves 

 no doubt as to its identity as a member of the family Astacina, 

 probably the Homarus vulgaris, M.-Edvv., a common Mediterra- 

 nean species. Nephrops norvegicus also occurs in the Mediterra- 

 nean; but as the only recorded localities are in especial the 

 northern parts of the Adriatic, and points westward of that gulf, 

 this noble representative of a former fauna seems not common 

 on the Grecian coasts. 



The diagnostic characters mentioned are : — the three anterior 

 foot-pairs are didactyle ; the pincers are larger than in Carabus, 

 unequal, with sharp spines along their outer margin ; the outer 

 antennae shorter than in Carabus, the inner bifid, or rather, as 

 Aristotle describes them, two on each side; the eyes are smaller 



