154 BULLETIN OF THE 



Family MATUTIDAE. 



Tin' Matutidae may conveniently be dividefl into two subfamilies, Ma- 

 tutinae and Hepatinae. Tlie latter gi p differs from the former in hav- 

 ing a broader carapax, a narrow facial region, and short orbits and eyes. 



Subfamily HEPATINAE. 



Osachila nov. gen. 



This genus is allied to Hepatus in all essential characters, but differs 

 considerably in the shape of the carapax, which is nearly as long as broad, 

 and lias the front much produced, so much so as to form a true rostrum in 

 one species. The carapax i- also more or less depressed and expanded at 

 i he -ides, and its surface is verj une\ en, Inn ing six chief protuberances. 



Species of this genus are found in the seas of both sides of Tropical 

 America. The name is that of a Florida. Cacique. 



Osachila tuberosa nov. sp. 

 Carapax somewhat octagonal, very slightly broader than long; surface 

 very uneven, deeply pitted on the protuberances, and finely, densely punc- 

 tate on tin' depressed parts. Three of the protuberances are on the 

 gastric region and correspond to the metagastric and nrogastric lobes, 

 the protuberance of the latter being much the smallest, and continued an- 

 teriorly in the form of a slight ridge in the furrow between the metagastric 

 lobes, reach in-, with the furrow.-, nearly to the frontal region. The cardiac 

 protuberance is rounded and smaller than tin- metagastric ones. Themeso- 

 branchial lobes are strongly protuberant and larger than the metagastric, 

 and there is a small, elongated, longitudinal protuberance between them 

 and the. cardiac protuberance. The front is projecting, and bilobed, with 

 the lobes verv obtuse and separated h\ a deep tin row. No protuberance on 

 the concave hepatic region. Antero-lateral margin straight or slightly con 



cave anterior!} , but quickly curving backward and bee ing parallel to the 



axis of the body in the greater, posterior part oi its length; it is armed 

 with numerous small irregular teeth, and i> pitted above like the protuber- 

 ant parts of the carapax ; and the posterior tooth, which forms part of the 

 branchial protuberance, is larger than the others. Postero-lateral margin 

 nearly straight, obtuse, rugose, and armed with two or three tuberculi- 



torm teeth, of which one. separated fr the post* rior extremity of the 



carapax by a concavity, is the largest. Posterior extremity of the carapax 

 narrow, with a rugose and much-thickened margin concealing the base of 

 the alrdomen. Beneath, the entire surface of the carapax, maxillipeds, 

 sternum, abdomen, and of the base? of (he feet, is densely covered with 

 rather large pits, giving it a vcrmiculated or reticulated appearance. 



