Notes, iv. 8 — 9. 233 



dans les femelles. Son dessoits offre quatre paires de doubles filets veins, destines a porter 

 les oeufs. Plusieurs de ces filets existent dans les males, mais dans un etat rudimentaire. " 

 7. This is too absolute a statement; and elsewhere (Zf. ^. iv. 3, 2) A. speaking more 

 carefully says that the rule is general but not universal. There are some grounds for his 

 statement. " In many species (of the higher Crustacea) the chelas on the opposite sides 

 of the body are of unequal size, the right-handed one being, as I am informed by Mr. C. 

 Spence Bate, generally though not invariably the largest. This inequality is often much 

 greater in the male than in the female" {Darwin^ Desc. of Man, i. 330). There are 

 however some small Crustacea in which the right claw appears to be invariably the 

 bigger. Thus I found no exception to this rule in loo common hermit crabs that I 

 examined in succession. In Alpheus villosus also the right claw is always the 

 larger ; and in Nika the right anterior foot is chelate, but not so the left. 



8. Cf. iii. 9, 14, and ii. 3, Note 6. 



9. Cf. iii. I, 7. 



10. It has been stated recently {Land and Water, Aug. 20, 1870) that in lobsters the 

 right claw is the larger in one sex, the left in the other. This however was afterwards 

 contradicted by Mr. H. Lee ; and I have myself found it to be erroneous on examination. 

 So far then the statement in the text is correct. But there is no ground for the 

 further statement that the Astaci use their claws only for locomotion and not for 

 prehension. 



11. Cf. iv. 5, Note 2, and Introd. p. x. 



(Ch. 9.) 1. The Cephalopods are called by A. Malacia, i.e. Mollusca or soft animals, 

 and are defined by him (//". A. iv. i, 2) as bloodless animals that have their fleshy 

 parts outside, and their hard part, when there is any, within. They all have eight 

 legs, with suckers on them, in front of the head. The head itself is provided with two 

 jaws or teeth, large eyes, and a small brain enclosed in cartilage. These, and the 

 presence of an ink-bag, are the chief characters assigned to them by A., who mentions, 

 however, two other notable peculiarities, namely the adherence of the yelk-bag to the 

 head of the embryo (Z). G. iii. 8, 7) and the modification of one of the feet in the male 

 poulp to form an instrument of generation {H. ^. v. 6, 3 ; v. 12, 3 ; D. G.'\. \<„ 4). 

 The latter statement, repeated by Pliny {jSfat, Hist. ix. 74), refers of course to the 

 now re-discovered Hectocotylus, 



Aristotle divides his Malacia into two groups, (i.) Those that have a short body 

 and long feet, no "proboscides," and no internal bones; a division corresponding to 

 our Octopoda. (ii.) Those that have a long body and short feet, but in addition 

 have two long "proboscides," with suckers on them. They also have an internal 

 bonelike support. These are our Decapoda. 



Of the first gi-oup {Octopoda) there are, he says, numerous genera, (a) Those that have 

 a shell {ArgonautidcB). Of these he mentions two species ; the Nautilus, doubtless 

 Argonauta argo ; and another not determinable. (/3) Those that are without a shell 

 {Octopodidce). Of these he mentions the Poulps ; the Eledone, and the Bolitaena. (Cf. 

 Note 17.) 



Of the second group {Decapoda) he mentions three kinds. The Sepias, the Teuthides, 

 and the Teuthi. The Sepia has a broad and strong "os sepiae," of a texture between 

 bone and fish-spine, and spongy within. Its body is broad rather than long, though of 

 good length in comparison with the feet. It has a narrow fin encircling the whole 

 body. Its ink-bag is large and placed low down in the body cavity. This can only be 

 the modem Sepia ; probably Sepia officinalis, and perhaps some others, as A. speaks 

 of "the genus of Sepias" (//. A. iv. i, 2). The Teuthi and the Teuthides have a larger 



