LAND CRUSTACEANS. 



75 



The exopyloric ossicles (4, PI. III.), which lie in the roof of the pyloric division of the 

 stomach to the outside, and rather in front, of the medium pyloric ossicle, bearing to this 

 latter much the same relation that the pterocardiacs bear to the mesocardiac, are stout, 

 broad, and roughly diamond-shaped. One diagonal runs transversely and the other fore 

 and aft. The hinder angle is rounded. The whole ossicle has a saddle-like double curva- 

 ture, and its outer surface is roughened. The pyloric ossicle (6, PI. III.) consists of two 

 parts — an anterior expansion, and a hindward median process from this. The anterior ex- 

 pansion lies with its long axis across the stomach. Its outer ends are thickened, and so 

 shaped as to embrace the ends of the prepyloric ossicle. These thickenings each send 

 backward a very narrow strip to border the hindward process of the ossicle. The whole 

 middle region of the ossicle, between the thickenings, is thin, and of a membranous, or, 

 in the hinder part, cartilaginous consistency. 



The urocardiac ossicle (27, PI. III.) is an oblong, semi-transparent plate, of simple form, 

 lying in the anterior wall of the dorsal hollow of the stomach, with its long axis fore 

 and aft. Its anterior end abuts on the mesocardiac ossicle, from which, however, it is 



EXPLANATION OF PLATE III. 



Reference Numbers. 



Fig. a. Stomach of Coenobita perlatus from the left side. 



Fig. B. Ditto, from above. 



Fig. C. Ditto, from below. 



Fig. D. Ditto, with roof of cardiac portion removed and the pyloric portion opened along the middle of the 

 roof, the side walls being reflected. 



Fig. E. Median tooth of same from within. 



Fio. F. Liver of Coenobita clypeatus, ventral view. 



Fig. G. Mid- and hind-gut of same species ; portions opened to show texture of lining. 



Fig. H. Green gland of same species from above. 



Fig. K. Generative glands ; a, ovaries of Coenobita clypeatus ; b, ovaries of C. perlatus ; c, testis of C. clypeatus. 

 Anterior end towards bottom of plate in each case. 



10—2 



