500 H. Richardson — Isopods of the Bermudas. 



ONISCOIDEA. 



Family Tylides. 

 Tylos Latreilli Audouin and Savigny. 



Plate XL. Figure 56. 



Tylos armadillo Latreille, Ctivier Regne animal, ed. 2, iv, p. 142, 1829. Gnerin, 



Iconogr. Crust., p. 35, pi. xxxvi, fig. 4. 

 Tylos Latreilli Audonin and Savigny, Descript. de I'Egypte, p.' 285-87, pi. 



xiii, fig. 1, 1827. Milne-Edwards, Hist. Crust., iii, p. 188, 1840; Eegne 



anim. Crust., pi. Ixx, bis., f. 2. Lucas, Expl. d'Alg., i, p. 73, 1849. 



Heller, Verb, zool.-bot. Ver., Wien, xvi, p. 733, 1866. Miers, Proc. Zool. 



Soc. Lond., p. 674, 1877. Budde-Lund, Crust. Isop. Terrestria, p. 273, 274, 



1885. (See Budde-Lund for synonymy.) 

 Tylos armadillo Dollfiis,* Mem. Soc. Zool. de France, p. 550, 1896. 



Body elliptical in outline, very convex, and able to be contracted 

 into a ball. Surface smooth or miuutel}^ granular and seligerous. 

 Color yellow or light brown, marked with black spots. 



Head with front not marginate ; lateral angulations produced into 

 lobes, which are truncate. Epistome forming a triangular shield, 

 advancing some distance beyond the surface of the head. Eyes situ- 

 ated post-laterally. External antennae, with a five-jointed peduncle 

 and a flagellum consisting of four joints, extends to the posterior 

 margin of the second thoracic segment. 



The seven thoracic segments are subequal. The epimera of the 

 first segment are represented by a thickening of the lateral edge, 

 which is incised or cleft posteriorly. The epimera of all the other 

 segments are dorsally separated by distinct suture lines. 



The first two abdominal segments have their lateral margins cov- 

 ered by the seventh thoracic segment. The three following seg- 

 ments complete the elliptical outline of the body, their lateral margins 

 forming a line curving inwards towards the terminal segment. The 

 last abdominal segment is quadrangular in outline, its post-lateral 

 angles rounded, and extends a little distance beyond the epimera of 

 the preceding segment. The uropoda are transformed into opercular 

 valves. At the ])osterior end of each large lamellar valve is a small 

 setose joint. The third, fourth and fifth abdominal segments have 



* In the Bull. Soc. d'Etudes Scientifiques de Paris, xiitb year, pi. i, fig. 4, 

 1890. Dollfus gives figures of Tylos niveus Budde-Lund and Tylos Latreilli 

 Audouin and Savigny. 



