MAIOPSIS. ll 
The orbital region of A. hystrix does not differ from that of A. rissoana 
but for the presence of a prxocular spine, a character which by itself cannot 
be considered of generic importance, as Mr. Miers admits.* Through hystria 
we pass by a gentle transition to such species as wmbonata, carpenteri, and 
crassa (species placed in the genus Seyramathia), in which the orbit is better 
defined through the projection of the brow. 
Thus the passage from the Inachine to the Maiine type is so gradual as 
hardly to justify a family division such as is proposed by Mr. Miers.t In 
the series of species, all of which are assigned to the genus Anamathia, family 
Inachidw, by Mr. Miers ¢ (rissoana, hystrix, pulchra, crassa), we pass from the 
strictly Inachine orbit of rissoana to an orbit like that of crassa, which is 
practically the same as that of Chorilia longipes, a species assigned by Miers 
to the genus Hyastenus in the family Maide. 
The orbital region is subject to a great amount of variation even in a 
single species (A. wnbonata), so that within the bounds of mere individual 
variation the passage is made from the Inachine to the Maiine type of orbit 
as exhibited in Chorilia. § 
MAIOPSIS Fax. 
Bull. Mus. Comp. Zodl., XXIV. 150, 1893. 
Carapace subtriangular, as broad as long, spinose; rostrum produced 
anteriorly into two divergent horns with an accessory spine upon their 
outer margins; interorbital space broad. Kyes small, eyestalks slender, 
retractile within the orbits. Orbits large, with a forward aspect, incomplete 
below, the upper margin prominent, with two deep fissures, and supraocular 
spines. Epistome short. Basal segment of antenne very broad, with three 
prominent spines upon its anterior margin ; flagellum of the antenne widely 
separated from the cavity of the orbit by a broad process of the basal seg- 
ment. Merus of outer maxillipeds notched at the antero-internal angle. 
Legs of moderate length ; carpus of chelipeds elongated, not carinated ; chela 
elongated and slender, fingers canaliculate within, but not spoon-shaped at 
their tips, their prehensile edges meeting throughout most of their length, 
* Journ, Linn. Soc. London, Zodl., XIV. 658, 1879. 
+ Op. cit., p. 640. 
¢ Challenger Brachyura, p. 26, 1886. 
§ See M. J. Rathbun, Proc. U.S. Nat. Mus., XVII. 61, 62, Plate I, 1894. Cf. Fig. 3 (orbit of 
A. umbonata) with Fig. 1 (also 4. wmbonata), and then ef. Fig. 1 with Fig. 5 (Chorilia longipes). 
