116 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.2 



in good enough condition to permit the comparison of characters that 

 are of importance in distinguishing the species of Lythrypnus, namely, 

 the length of the dorsal spines and the posterior rays in the dorsal and 

 anal, and the number of scales. The two populations are therefore 

 tentatively recognized as distinct species, pending the comparison of 

 more specimens in a better state of preservation. 



PARR ELLA, new genus 



Genotype, — Parrella maxillaris, new species. 



A definition of the genus is included in the description of the geno- 

 type. Parrella is structurally nearest to Microgobius. The genotype 

 diilers from all known species of Microgobius by having large scales, 

 fewer rays in the dorsal and anal, a subterete head, a notably more slender 

 body and longer pectoral, and a different color pattern. The most 

 striking differences, however, are found in the distribution of the lateral 

 line organs. These structures which are of considerable importance in 

 classification will be considered in a systematic manner in a forthcoming 

 paper. 



I take pleasure in naming this genus after Professor Albert E. Parr 

 of Yale University. 



Parrella maxillaris, new species 



Description. — Body notably slender, compressed ; head subterete, the 

 depth slightly less than the width. Mouth terminal, very moderately 

 oblique, a horizontal through distal margin of upper lip passing approxi- 

 mately through lower margin of eye; lower jaw equal anteriorly to 

 upper. Maxillary long (at least in male), its posterior end falling only 

 about a pupil's diameter in front of preopercular margin in two males 

 41-43 mm, almost to the same relative point in one male of 28 mm. 

 Tongue moderately emarginate. Teeth in 3 or 4 irregular rows at 

 symphysis, tapering to one or two rows on side; teeth in outer row in 

 both jaws larger than posterior ones, those in outer row of upper jaw 

 somewhat larger than corresponding teeth of lower jaw; a few inner- 

 most teeth at symphysis of lower jaw subequal to those in outer row 

 of upper jaw; no caninoids. No papillae or flaps on shoulder girdle. No 

 sharp ridge or crest in front of dorsal. Isthmus rather broad, attachment 

 of gill membrane nearly at lower angle of pectoral base. Scales large, 

 about 32; none on antedorsal distance, side of head, base of pectoral, 



