ME. E. J. MIEES ON THE IDOTEIDiE. 75 



shorter ; all Lave concave anterior and posterior margins, with 

 the subtriangular lateral plates (coalescent epimera ?) broad 

 thick, narrowed anteriorly, separated one from another, directed 

 forward in the three first segments and backward in the three 

 last. Postabdomen short, broad, very convex, with subparallel 

 sides at base, narrowed posteriorly, with rounded apex, composed 

 of two distinct segments — the first short, the second very large, 

 scutiform, longer than broad. Eyes placed at the sides of the 

 head, near the postero-lateral angles, small, black in the young, 

 diminishing and becoming almost invisible in the adult. An- 

 tennules and antennae short, thick, subequal, inserted in front of 

 the head, composed of six joints, the last four larger than the 

 basal, equal in length, but diminishing in] diameter from the first 

 to the last, which is conical and ends in a pencil of hairs ; the 

 second antennae are inserted beneath the first and in the same 

 vertical line. Legs little-elongated, robust, cylindrical, all ter- 

 minating in a strong reflexible claw ; the legs of the first pair 

 much shorter than the rest, which are subequal. Colour yellow, 

 variegated with grey. Length 2 lines (in the plate | inch, nearly 

 7millim.). 



The author, in his description, mentions two large lateral plates 

 of the postabdomen which are applied to and cover in large 

 measure the ventral surface, by which, no doubt, the plates of 

 the operculum are intended. 



The Upelys annulcdus, which I regard as probably the young 

 of Desmarestia cliiJensis, is described by Dana as narrow, sub- 

 elliptic. Head transverse, rather longer than first thoracic seg- 

 ment ; frontal margin apiculate in the middle, a little concave 

 on either side of the median prominence ; antero-lateral angles 

 rounded. Thoracic segments all short, prominent, transverse, 

 nearly equal in length, the last four a little separated on each 

 side, the tliree posterior sublunate (when viewed from above). 

 Postabdomen 2-joiuted ; first segment very short, nearly obsolete, 

 much narrower than tlie following; the second scutellate, tri- 

 angular behind ; the sides towards the base about parallel. Eyes 

 minute, remote. Antennules a little shorter than the antennae, 

 4-jointed, third joint a little longer than the others. Antennae 

 5-jointed, not longer than the breadth of the head ; joints short, 

 the last three a little the longest. Legs subequal, similar in 

 form, and terminating in a small claw ; all rather short, the first 

 pair the shortest. Length ^ inch. 



