464 Illustration of Squilla DesmareslW. 



so as to receive the next adjoining part : much in the same 

 manner as the blade of a clasp knife is received into the handle. 

 The pectinated joint is inserted into the first groove on the 

 inside, and seems protected by a finely serrated edge on the 

 outer side of the arm. In this groove each spine [of the pec- 

 tinated joint] has a separate cavity to receive it ; and when it 

 is closed, the animal elevates three movable spines, which lie 

 on the inner edge of the second joint in front, which in some 

 measure supply the place of the closed hand, and are used as 

 hooks or fingers. In d, in Jig, 39., are shown the under side 

 of the caudal case, and penultimate segment with its lateral 

 processes, strongly spined and ciliated, which together form 

 the fan-like termination of the bodies of the crustaceans of 

 the order Macroiira. The exterior spines on the processes 

 are movable. 



This Squilla I kept alive in a basin of sea water for two 

 days ; during which time I had a fair opportunity of observ- 

 ing its activity and peculiar habits. It sported about, and, 

 after a first approach, exhibited a boldness rather unexpected. 

 When first alarmed, it sprang backwards with great velocity ; 

 after which it placed itself in a menacing attitude, which would 

 rather have excited the fear of exposing the hand to it. The 

 prominent appearance of the eyes, their brilliancy and attentive 

 watching, the feeling power of the long antennae, evinced 

 quick apprehension and instinct. I brought a silver teaspoon 

 near them, which was struck out of my hand with a sudden- 

 ness and force comparable to an electric shock : this blow was 

 effected by the large arms, which were closed, and projected 

 in an instant with the quickness of lightning. An apparent 

 anxiety to keep the head and claws in front made me suspect 

 that the animal lodges its hinder part in holes or recesses, 

 from which it can strike at its prey or other passing objects. 

 The attitude represented in the figure {Jig, 39.) was main- 

 tained during my observations ; and I did not see any inclina- 

 tion to close its tail in a more compacted form. 



In 1820, I mentioned the existence of this genus on our 

 coast to M. Latreille ; who remarked, en passant, " Oui, je les ai 

 vus sur nos cotes : " but I suspect that this celebrated natu- 

 ralist alluded to the Mediterranean coast, as I have not heard 

 of their appearance on the Atlantic side of France. 



I doubt not that that described by W. Yarrell, Esq., VI., 

 230., from Cornwall, will prove, on examination, to be the 

 same as mine ; although the caudal case and spines, the shape 

 of the processes, and the want of feelers in the exterior an- 

 tennae, denote some differences. The publication of this notice 

 may lead to clearing up the doubt. — Guernsey, May, 1835. 



