DESCRIPTIONS OF PREPARATIONS. 



where the (hitinoid eoat is divided into arcac corresponding, as on the carapace, to 

 the individual cells. The cutieular coat of the stomach ends at the pylorus with 

 Jive projectm;; processes ; that ot the intestine commences with si\ elevations pro 

 longed into lidgcs \\hi. h tiaverse the tube in a spiral fashion. Mcncath the ehitmoid 

 coat is the single lavci ot . \ 01 c. lodeim . ells, 1.,,-e in si -c. and then a 



fibrous membrane followed by a layer of cellular connective tissue \\in. h incloses 



mus. le fibres, both longitudinal and en. ular, in the stomach and intestine. 



The chitmoid la\ei ol the stomach is tin. kcned in the dorsal and lateral walls 

 to form certain ossicles which, accotdmg to \ it on, have the same structure as 

 the carapace. Some ol these ossicles have simply a supporting function, others 



constitute the 'gastric mill/ The latter are named and arranged as follow, Thew 

 is a cardiac ossicle crossing the cardiac region transversely, articulating lateiaiiy 



with a -:./, ..:'.:'.,;. piece, and extending loiu.nds into a sutler disc upon which the 

 anterior gastric muscles are prmetpalU mseited. and ba.Uaid-. into a n.niow .;>,' 



cardiac piece which is produced interiorly into two accessory or m//; teeth, ,ud. 

 mentary in the Lobster. A pyfarit ossicle crosses the pyloric region transversely and 



dorsallv, and skives insertion to theposteiioi gastric muscles. It articulates in I. out with 

 a -. -M.',''/. ossicle \\ln.h is bent downwards so as to lonn with it an acute angle 

 ku kwatds way, and ailu nl.ites ,n tuin \\ith the .</,.,//.//,.. piece (.s///V/). ( 'lose to this 

 aiticulation the ;'-. r.'./. ossicle is piodueed into a /-.;//./ /v. .:'/,//: tooth, single in 

 the I obster. The /M:',v/. ossicle aitunlates lateiallv .HI each side with a si;ovW/</,' 

 ossicle lying in the walls ot the cardiac region. This ossicle articulates at its outer 



extremity with the corresponding extremity of the pterv iticle (o^fw) oi Its 



own side. Its innci extremity bcais the iMcat seiiated .',//,-/,/.' tooth. Just below the 

 antenoi end ol this tooth pioject.s an /.;/,'/,' .',//,-/,/.' tooth borne by the 'lateral 

 rardia< piece' of Milne I'.dw.nds, one ol the supporting bars ot the stomachal 



walls. The stomach possesses extrinsic and Intrinsic muscles. Tlu- ioim.-i set 



includes the gastric muscles above mentioned, as well as the antenoi lateral, the pos 

 terior, supcrioi and inteiior dilators. The lattci set includes various mus< les. One 

 system ot fibres unites tli vul r.;, 1 . iclcs The i em. under, according 



to Mr, T. J, Parker, act as constrictors, especially a layei winch embraces the pylon.- 



n. This ici'.ion has its c.uitv, inou 1 pailtculailv in the postciioi pail, natioued 

 by the bulging inw.nd ot its side walls and the development of a median ventral 

 iidi'.c. Thcsuitaccs ot these pails ate beset with setae and forma most efficient 

 ' filter.' 



Theie is on either side of the stomach, at the entrance of the oesophagus, a 

 loun.l white spot caused by the presence ol a il.im.sh papilla having the same 



structure as the rest of the wall of the stomach. Forty days before a moult m the 



adult, oi loi a shorter period in the young according to age, the hitinogcnous cells 

 ot this papilla devclope a numbci ol minute knobbed pioeesses which raise the 

 ovcilvm: 1 , chitmous cuticle and c\'entually break up into corpuscle like bodies. 

 I'encath the cutu Ic. and between the ends ol the chitinogenous cells and then pro 

 ., lamellae ot .alcilied i>Jganic mattci are laid do\\n toiinm:', the .;,/*//('/////. 

 The lamellae are pierced by poics. Then suhstam e consists ol ( 'ah mm c.nbunati', 

 with a small admixtme ol phosphate, and ol organic substances p.nllv -.nluble in walei, 

 paith -insoluble, and pcihaps chitmoid in nature. Ihiini!', t he de\ vlopincnt ol the 

 v.astrolith the papilla becomes more piomment and changes ttl '-hape 1'lu- lullv 



