562 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.51. 



the foot opening. Near the middle of the body two inclined trans- 

 verse ridges on each side originate from the lateral longitudinal ridges 

 and disappear before reaching the dorsal keel. On the ventral sur- 

 face of the lorica a median ridge, beginning near the anterior sinus, 

 reaches as far as the middle of the body and joins a curved transverse 

 ridge, passing entirely across the ventral plate and joining the lateral 

 ridges. 



The anterior opening of the lorica is elongate oval, continued dor- 

 sally and ventrally as a fairly deep sinus. The opening for the foot 

 is large and ovate, its edges apparently curving inward, so that the 

 border is rather ill-defined. 



The lateral antennae are situated some distance above the lateral 

 longitudinal ridges and immediately behind the posterior pair of 

 transverse dorsal ridges; the sensory setae project through small 

 conical prominences on the lorica. 



No material suitable for a detailed study of the corona was avail- 

 able, but as far as may be judged from preserved specimens, it does 

 not differ materially from the type of Trichotria ( = Dinocharis) . 



The foot is about one-fourth the length of the lorica and decreases 

 considerably in size toward the toes. The posterior segment is well 

 marked, but anterior segments are rather ill-defined; apparently two 

 are present. The toes are stout at the base, and the posterior half 

 is very slender and slightly decurved. 



The trophi are malleate, resembling closely the EucManis-tjpe and 

 differ only in minute details in the two species. Figures 11-13, plate 

 97, are drawn from L. oxysternon. The rami are elongate and trian- 

 gular; on the upper surface of the right ramus there are three promi- 

 nent transverse ridges continuing over the inner edge as blunt, knob- 

 like teeth, which interlock with two similar structures on the left 

 ramus. The unci are six-toothed; the right uncus has three strong 

 clavate and three linear teeth, while the left uncus has two olavate 

 and four linear teeth. The clavate teeth on each side rest in the 

 grooves between the transverse ridges on the rami, and all six teeth 

 of one uncus are opposite the interspaces of the other. The fulcrum 

 and manubria offer nothing of special interest. 



The genus includes but two species, and vfhile the original descrip- 

 tions are perfectly clear the two forms have for many years been 

 considered varieties of a single species; the records are consequently 

 so inextricably confused that it is rarely possible to decide positively 

 which animal they refer to. Only such citations as appear with 

 reasonable certainty to be assignable to one or the other species are 

 given in the synonymy. 



