CALIFORNIA STALK-EYED CRUSTACEA. 85 



as the fourth, the sides strongly convex; fifth segment scarcely longer than 

 the fourth and shorter than the sixth; last segment triangular, acute. 



Length of carapace, 18.5 mm.; width of carapace, 21 mm.; width of 

 front, 11.2 mm. 



San Diego, California. Collected by A. U. Crawford. 



This species is described from a single dried and 

 somewhat imperfect specimen contained in the Museum 

 of the University of California. The form and arrange- 

 ment of the antennae and antennules could not be 

 determined, nor could I make out whether or not the 

 inferior orbital lobe was in contact with the front. The 

 front, legs, maxillipeds, and striations on the carapace 

 are similar to those of Pachygrapsus, but the character 

 of the orbits separates it from that genus as well as all 

 the other genera of the Grapsidse. 



Family PINNOTHERID^. 



Carapace convex or depressed, often more or less membranaceous, the 

 autero-lateral margins entire or very slightly dentate. Front narrow. 

 Orbits and eye-peduncles very small. Buccal area convex anteriorly. 

 The merus and often the ischium of the maxillipeds is well developed, 

 and the palp may be joined to the summit, antero-internal angle, or, 

 rarely, the antero-external angle of the merus. Chelipeds usually small, 

 or of moderate size. Ambulatory legs variable; dactyls generally styliform 

 and not armed with spines. 



The members of this family are generally of small 

 size, and most of them inhabit the shells of bivalved 

 molluscs. Some species inhabit the intestine of echino- 

 derms and others the tubes of annelid worms. The 

 Pinnotheridse are divided by Miers into four subfam- 

 ilies, only two of which are found in our limits. 



Subfamily PINNOTHERIN^!. 



Carapace usually convex, subglobose, or transverse. Front not ros- 

 trated. Ischium of the maxillipeds rudimentary or absent. The ambu- 

 latory legs are all well developed (the last pair is sometimes small); 

 dactyls often short. 



