SCHIZOPOD FEOM TASMANIA. 299 



there is uo appendage of the intestine, though this is present in others. In all the 

 Tlioracostraca the liver is in the form of a moi'e or less compact mass composed of 

 numerous small caeca. In Amphipoda (e. g. Gammarus '*) a single pyloric caecum opens 

 just beliind the stomach, and this is also jirobably salivary in its function; while at the 

 posterior end of the mid-gut two slender cylindrical processes open into the intestine. 

 These caeca are placed along the dorsal surface of the intestine, antl reach as far forward 

 as the last thoracic segment. Their function is probably nrinary. In CaprcUa deutafaf 

 a single pyloric ctccum is placed dorsally to the posterior part of the stomach and opens 

 in the front part of tlie intestine, while near its posterior extremity the intestine carries 

 a small simple caecum very similar to the posterior one in Anaspk/e.s. 



In the Schizopod under consideration tlie stomach is hardly separable into a cardiac 

 and pyloric portion, nor is the separation between the hind part of the stomach and the 

 intestine at all well marked. The liver is unique in its structure. There is no trace of 

 a pyloric caecum J, the first organ of the kind being placed as far back as the first 

 abdominal segment. Prom the imperfectly triturated condition of the food in the part 

 of the intestine which passes through the thorax, I am inclined to believe, as said 

 before, that the gastric function is only imperfectly performed by the stomach, and that 

 the anterior part of the intestine acts as part of the pyloric stomach. If this be so, the 

 anterior cfecum may still function 2iartly as a salivary organ (though this is hardly 

 probable), and the posterior one, Avhich is placed far back in the alimentary canal, may 

 be excretory only and may act as a urinary gland. It is clear, however, that the whole 

 structure of the alimentary canal bears a closer resemblance to the lower Amphipoda 

 (Caprellidaj) than to any of the higher forms of Crustacea, and this is probably to be 

 looked on as another survival of a primitive type of structure. 



The circulatory apparatus has been shown to be very elementary in its structure. In 

 the Brachyura the heart reaches its maximum development, occurring in most crabs as 

 a short polygonal vessel placed in such a central position as to readily control by its 

 rhythmic action the blood-supply of the body. In Macroui-a it is also a well-developed 

 saccular organ, from which the passage of the various arteries can readily be traced. In 

 Schizopods, though not so well developed, it still preserves its saccular character. But in 

 Anaspides it is apparently reduced to a simple tube. Only in the Stomatopoda, among 

 the higher Crustacea, is there any approach to such a primitive form. 



It is premature, with the imperfect knowledge of this animal still at our disjjosal and 

 our absolute ignorance of its development, to attempt to frame any genealogical scheme 

 showing its position among the Schizopoda, but from the points referred to I thmk it 

 probable that the Ajiaspidae and the Euphausiidte were somewhat closely allied in their 

 origin. 



*^Sars, Crustacc's rl'eau douce, p. 5-5. 



t 1*. Mayer, ' Die Caprelliden des Golt'es von jS'capcl,' p. 147, Taf. 9. figs. 2, '■'>, and 4. 



% This statement must be accepted with the reservation due to tlie fact that 1 could not make out this feature 

 clearl}', but it appeared to me as if the upper part of the pyloric portion of the stomach was enveloped in an easily 

 disintegrated tissue of which I could not trace the close connection with the alimentary eanal which certainly 

 existed. "Whether this tissue represents an imperfectly developed pyloric caecum, or an anterior process of the liver, 

 I have not succeeded in demonstrating. 



