170 



CALIFVnSIA ACADliMY Ol' SC'IENOES 



One specimen with 18 rays in the dorsal lias 17 in the anal. In all other 

 cases the two fins agree. All specimens possess a sharp thin dermal fold which 

 extends from the first dorsal spine, to the hase of which it is attached, forward over 

 na|>e anil occijmt to a point immediately hehind the eyes. A similar fold exists in 

 ^f. signatus, and will douhtless be detected in M. thalassinus. It does not exist in 

 M. gttlosus, which is in other respects less closely allied to the species under con- 

 sideration, and will douhtless in time receive genorie recognition. A similar fold is 

 found in Uobiits nicholsi, and again, in an exaggerated form in LopJiogohluf, cij2>rinoidcs. 



M. emhlematicus is most nearly allied to M. thalnssimts, which it seems to 

 represent in the Pacific. No structural features which promise to be permanent 

 are alleged to distinguish them, but we have no specimens of thalai^siHus at hand for 

 comparison. It seems altogether probable that M. eulejns, from Fortress Monroe, 

 is a synonym of .1/. tha/ai^simts. 



Measurements in Hinidredlhs of Lenglh without Caudal. 



Total length in mm 



Lengtli to base of caudal in mm 



Head 



Snout 



Eye 



Interorbital width 



Maxillary 



Depth of body 



Depth of caudal peduncle 



Longest dorsal spine 



Longest dorsal ray 



Longest caudal ray 



Longest pectoral ray 



Longest ventral ray 



318. Microgobius miraflorensis sp. nov. 



Plate XXIX, Fio. 54. 



A species with comparatively large ctenoid scales, with produced spinous dorsal, and with 

 plain coloration. Resembling in general appearance M. cmblematicus, hut the body less elongate, 

 the mouth larger, the caudal more produced, the scaling and the coloration entirely different. There 

 is also lacking the cutaneous fold on nape and occiput. 



Head 3i in length; depth 5. Maxillary i^ in head; eye 3J. Dorsal VII, 17. Anal 17; 

 the last ray split to the base, the two halves separated for half the distance found between distinct rays. 



