238 MR. MIERS ON A THELI'HUSA FROM KILIM A-N J ARO. [Mar. '6, 



carapace adjoining the antero-lateral angles of the buccal cavity are 

 very distinctly granulated. Tlie eye-peduncles are slender (for a 

 species of this genus), and the eyes do not attain the exterior angle 

 of the orbit. The exterior maxillipedes are formed as in T. perlata, 

 having the ischium and merus of the endognath distally truncated, 

 the merus rounded at its antero-external angle, and scarcely emar- 

 ginate at its antero-internal angle. The chelipedes in the adult 

 male are unequal, the right the larger ; in both the merus is armed 

 with a series of spinules on the anterior margin, and with a somewhat 

 longer spine near the distal extremity ; the carpus with a spine 

 followed by a smaller spinule on the inner margin ; the palm is 

 somewhat compressed and nearly smooth, rounded above ; the 

 dactyl and poUex are denticulated on the inner margins, and have 

 between them, when closed, a rather narrow interspace ; the dactyl 

 is slightly arcuated and as long as, or rather shorter than, the palm. 

 The ambulatory legs are of moderate length, with the fourth to 

 sixth joints compressed, and vrith the superior margins acute ; the 

 margins of the penultimate joints near to the distal extremity and 

 the dactyli are armed with small spinuliform teeth, which on the 

 dactyli are disposed in four longitudinal series. 



Adult male. 



lines. millims. 



Length of carapace l?^ 37 



Breadth of carapace about .... 25| 54*5 



Length of a chelipede 44 93'5 



This form may be distinguished from other African species in 

 which the postfrontal crest is distinctly developed, by the following 

 characters : — From T. perlata, M. Edw., which is found at the Cape 

 and Port Natal, by the wider transverse carapace, which is more 

 dilated at the branchial regions, and not dorsally granulated near 

 the antero-lateral margins, and by the form of the orbit, whose 

 inferior margin is regularly concave (not as in specimens referred to 

 T. p€7-Iata in the Museum Collection), abruptly angulated near the 

 interior subocular lobe. From T. injlata, M. Edw., by the less 

 convex carapace, straight postfrontal crest, and the granulated 

 line which borders the antero-lateral margins of the carapace. 

 T. aubryi, M. E., T. africana, A. M. E., and T. emarginata, 

 Kingslev, from the Gaboon, West Africa, and Port Natal, have an 

 additional tooth between the exterior angle of the orbit and the 

 postfrontal crest. In T. goudoti, M. E., from Madagascar, the 

 postfrontal crest is less developed, and the immobile finger of the 

 chehpedes forms more or less of an angle with the inferior margin of 

 the palm. Another species from Madagascar, T. madagascariensis, 

 A. M. E., which has not, I behevc, been figured, is distinguished by 

 the lesser development of the postfrontal crest and the straighter 

 fingers of the chelipedes, which meet along their inner margins. 

 In the West-Aliican 2'. bayoniana. T. anchieice, and T. dubia, 

 Brito Capello, the lateral epibranchial tootii is more developed. In 



