108 
THIRTEENTH REPORT. 
REPORT OX THE CRUSTACEA COLLECTED BY THE 
SITY OF MICHIGAN- W A L K E R EXPEDITION IN 
STATE OF VERA CRUZ, MEXICO. 1 
UNIVER- 
THE 
A. S. PEARSE. 
The University of Micliigan-Walker Expedition (summer of 1910), 
under the direction of Dr. A. G. Ruthven, obtained representatives of 
eleven species of crustaceans, four of them new, in southern A" era Cruz. 
The following paper is the result of the study of this material and con- 
tains the descriptions of the new species. 
Most of the specimens were collected on the hacienda of Cuatotolapam 
which is on the plain at the base of the San Andreas Tnxtla mountains 
and in the canton of Acayucan (elevation fifteen meters). Several 
species were taken at Lake Catemaco, at an elevation of 298 meters, in 
the San Andreas Tnxtla range. 
The numbers given to the specimens refer to the University of Mich- 
igan Museum catalogs. 
COPEPODA. 
1. Cyclops leuckarti Claus. — Six individuals of the species were col- 
lected with a Birge net from La Laja creek at Cuatotolapam on August 8. 
1910. 
OSTRACODA. 
2. Cypridopsis sp.— Several specimens thus identified by Prof. Sharpe 
were taken in the shallow water in Lake Catemaco on July 27. 
ISOPODA. 
O 
•>. 
Cubans loalkcri, new species. — Body convex, minutely granulate; 
thoracic segments each with an elongated swollen mass of blended 
tubercles on each side 1 mm. from the middle line. Head more than 
twice as wide as long; anterior margin straight, strongly reflexed; eyes 
rather large, sixteen ocelli. Antennae with flagellum shorter than last 
joint of peduncle; first joint of flagellum less than a third as long as 
second. First segment of body separated by grooves from the lateral 
margins which are somewhat reflexed ; lateral margins of other thoracic 
segments narrow, strongly flexed posteriorly; first coxipodite free along 
whole outer margin, divergent at posterior end; second coxipodite free 
along outer end and anterior margins, divergent at outer edge, rieotel- 
son strongly constricted in the middle, about as wide as long, width 
at distal end one-fourth less than at proximal end; a low tubercle near 
i When Dr. Pearse was called to the University of the Philippines, in April, 1911, this paper was com- 
pleted except for the identifications of the ostracods and shrimps, and two species of Isopoda. He 
had already submitted the ostracod material to Prof. R. W. Sharpe for identification, and the other 
undetermined specimens were later sent to Miss Mary J. Rathbun of the U. S. National Museum. A 
snec imen of Probopyrus bithynis found by Miss Rathbun on one of the shrimps and another species of 
isonod (Porcellio rathkei) that had not been submitted to Dr. Pearse were identified by Dr. Harriet 
Richardson The Museum is indebted to these persons for their assistance. 
V general account of this expedition will be published in the annual report of the head curator of the 
University of Michigan Museum for the year 1910-1911 .— Alexander G. Ruthven. 
