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The (lii!,eslive tract of Lininoria consists of the oesophagus, the masticatory stomach 

 containing the gastric mill, the intestine and the anus. The mouth (mo., fig. 129) 

 opens into the oesophagus between the mandibles and the overhanging upper lip or 

 labrum. The latter tits closely against the mandibles. It bears a set of very fine parallel 

 teetli. The oesophagus (oes.) is a nearly straight tube lined with chitin. It enlarges 

 under the brain to form the stomach. 



This masticatory stomach is lined with chitin and its walls are much toldud, form- 

 ing the characteristic plate-like processes found generally in the Malacostraca. There 

 are nine of these processes in the gastric mill of Limnoria. We will designate them as 

 the paired antcro-lateral, lateral, and postero-latcral, and the unpaired antero-ventral, 

 median and postero-dorsal . Of these, the lateral process, the middle process and 

 postero-latcral processes are the largest. The others are less conspicuous, and appar- 

 ently were overlooked by Hoek (1893) in his description of the gastric mill. 



The lateral processes {lat., figs. 129 and 130, 1) are situated just posterior and 

 dorsal to the smaller paired anterior-lateral processes (a. -I. p.). They carry large bristles 

 with forked ends which point inwardly and posteriorly. There is a hea\y muscle 

 bundle which is inserted on the side and originates in the roof of the head. The floor 

 of the gastric mill and stomach is considerably thickened and several muscle bundles 

 are inserted at this level (muse). As Hoek did not observe the most anterior of the 

 lateral processes, those structures which he calls the "antero-lateral processes" are 

 here designated as the lateral processes. 



The postero-lateral processes (p. -I. p.. fig. 129) are paired and arise from the 

 ventral wall of the gastric mill, on both sides of the mid-line. Their dorsal surfaces 

 are flat and the sides concave. At the posterior end of these processes, close against 

 the wall of the gastric mill, they bear two small prolongations. Narrow strands of 

 chitin are attached to these prolongations and trail posteriorly into the intestine. 

 The postero-dorsal process (p.-d. p.) also ends in chitinous strands at the same level. 

 The median process (mcd. p.) arises at nearly the same level as the lateral process, and 

 anterior to the postero-lateral processes. It consists of a ridge in the mid-ventral line, 

 and lies between the postero-lateral processes. These processes overhang it in the 

 mid-line. Its anterior part bears very fine hairs, but that portion lying between the 

 postero-lateral processes does not appear to have these hairs on its surface. The 

 middle piece is much reduced at the posterior end of the gastric mill. At this level two 

 ducts from the livers empt\' into the cavity lateral to the middle process and between 

 the overhanging portions of the postero-lateral processes. 



On account of the liberal supph' of muscles to the gastric mill there is little 

 doubt that these processes can be brought into play as grinding mechanisms. This is 

 in accord with the general view that the gastric mill is primarily an organ for the 

 trituration of ingested material. The large bristles on the lateral processes, the sharp 

 chitinous edges of the postero-lateral processes, and the pointed, spine-like protrusions 

 on the antero-lateral and antero-ventral processes lend further support to this view. 



Just behind the masticator>- stomach, the two li\'er ducts (/. d., fig. 129) open into 

 the digesti\e tube. These openings are always into the endodermal mid-gut, but the 

 posterior limits of this morphological region have not been determined in Limnoria, 

 so the rest of the digestive tract is referred to as the intestine (int., fig. 129). The anus 

 {an., fig. 129) is on the ventral side of the telson. 



The so-called liver consists of four elongated secretory caeca, a larger pair dorso- 

 lateral to the digestive tract and a smaller pair ventral to it (liep. c.d., hep. c, fig. 129; 

 Iv., fig. 130, 2). The two caeca on each side open by a common duct. 



The livers secrete a vellow crvstalline substance. These crvstals are character- 



